Presentation on theme: "Basics of Crop Production"— Presentation transcript:
1Basics of Crop Production Soil and Plant FertilityIf you are viewing this file with PowerPoint, simply use your F5 key to have it play full screen like a movie.
2Soil QualityThis is the most important factor in farm crop production.Soils will determine which plant species yields the most, the time of harvest, and ultimately the investment a landowner must make to yield an acceptable economic return from management.Soil quality is the most important factor in farm crop production. It largely determines what can be produced on the farm and directly affects the landowner’s economic investments on the farm. For this reason, soil quality gets a gold star for importance.
3Soil Profile The soil profile shows the layers, known as horizons that representthe soil.Horizons formed over the centuries due mostly form weathering.The soil profile shows the layers, known as horizons that represent the soil. Horizons have formed over the centuries due mostly from weathering. A lettering system is used to name the different horizons.A lettering system is used to name the different horizons.
4Where can you find info on a farm’s soil? In the County Soil Survey Map.There are Tables on several land options such as Woodland Management and Productivity which provides a lot of valuable information on the potential for soil erosion, seedling mortality, species preference, and tree growth.All of the information that you need to know about your farm’s soil can be found in the County Soil Survey Map. You can find a copy of the Soil Survey Map at your county Soil Conservation District. The Soil Survey Map has a wealth of information that includes tables that can help you to plan a forest planting.
5County Soils MapThere is even a table in the Soil Survey Map that evaluates sites for wildlife habitat.The Soil Survey Map even has tables to help you to plan a wildlife habitat planting.
6Factors Controlling Plant Growth LightMechanical SupportHeatAirWaterNutrientsAll except for light, involves soilThe 6 factors controlling plant growth are 1) light, 2) mechanical support, 3) heat, 4) air, 5) water, and 6) nutrients. Of these six, all but one, light, is supplied by the soil. Soil provides a place for roots to grow for support. Soil temperature largely regulates plant growth. As we will see shortly, one-half of the soil is made up of air and water. Soil contains minerals and organic matter that provide essential nutrients to plants.
7Major Components of Soil 50%This pie chart shows the four major components of a typical silt loam soil. The components are 45% mineral, 5% organic matter, 25% water, and 25% air. The thing to note here is that the soil is 50% air and water. This tells you that soil is not a solid thing. It is actually one-half pore space occupied by air and water. This is where the action takes place in the soil.
8Soil TerminologySoil texture concerns the size of mineral particles, specifically the relative proportion of various size groups in a given soilSoil structure the arrangement of soil particles into groups of aggregatesIt is important to know and understand the terminology used in agriculture. There are some key words and terms associated with soils that agricultural producers should know.Soil texture: concerns the size of mineral particles, specifically the relative proportion of various size groups in a given soil. (This will become clearer when we discuss the various soil texture types).Soil structure: the arrangement of soil particles into groups of aggregates.
9Soil TextureSoil texture is separated into three soil separates based on particle size.SandSiltClaySoil texture is separated into three soil separates based on particle size.1) sand2) silt3) clay
10Soil TextureSilt, clay imparts a fine texture and slow water and air movement, also high water holding capacitySandy to gravelly are referred to as lighter soils with lower water holding capacitySilt, clay: imparts a fine texture and slow water and air movement, also high water holding capacity.Sandy to gravelly: are referred to as lighter soils with lower water holding capacity.Silt and clay soils are referred to as not only fine textured soils but also as heavy soils. Clay, which is the finest soil particle, will produce the heaviest soils. Because the soil particles in silt and clay soils are small, these particles will be more densely packed with many small pore spaces. This causes water and air to move more slowly through them than in the coarser sandy or gravelly soils where larger pores allow more rapid movement. Due to the abundance of the pore spaces in fine textured soils, they are able to hold more water within them than in lighter soils. This is one reason why the fine textured soils can resist drying out longer than lighter soils.
11Soil TextureSandy soils are normally very well drained and often lack nutrients due to constant leaching loss.Mostly clay soils are at the opposite end of the soil spectrum. They tend to allow water to move through more slowly and will stay wetter longer. They will hold nutrients.Because they are generally well drained, sandy soils often lack plant nutrients due to constant leaching.Soils that contain mostly clay are just the opposite in that they tend to hold moisture and will retain plant nutrients. Leaching is less of a problem in heavier soils.
12Soil TerminologyPore space is that portion of the soil occupied by air and water- sandy soils have low soil porosity, while silt and clay soils have high soil porositySoil compaction fine textured, wet soils are more easily compacted- compaction reduces pore spacesWe saw in earlier slides that one-half of soil is made up of pore spaces, which contains air and water. Due to the greater abundance of these pore spaces, fine textured soils are able to hold more air and water than the lighter sandy soils with larger, but fewer pore spaces. Because of the small particles in fine textured, the soil is denser and therefore more sensitive to compaction when wet. Compacted soils have reduced pore space and are less productive. Soil activity for plant production takes place in pore spaces.
13Soil Terminology Soil depth - defined as that depth of soil material favorable for plant root penetration- deep, well drained soils are the bestSoil depth: defined as that depth of soil material favorable for plant root penetration. Soils referred to as deep and well drained are considered to be the best. A shallow soil would be one that has only a few inches of topsoil before getting into a less productive substrate material.
14Soil TerminologySlope land topography largely determines the amount of drainage, runoff, and erosion the steeper the land, the more management is requiredSlope: land topography largely determines the amount of drainage, runoff, and erosion. The steeper the land, the more management is required.
15Soil TerminologyOrganic matter it consists of plant and animal residues in various stages of decay- adequate levels benefit soil by:1) improving physical condition2) increasing water infiltration3) improving soil tilth4) decreasing erosion losses5) supplying plant nutrients6) holding cation nutrientsOrganic matter: it consists of plant and animal residues in various stages of decay. Adequate levels of organic matter benefits the soil in several ways:1) improves the physical condition of the soil,2) helps to increase water infiltration,3) improves soil tilth (those properties of soil that are conducive to plant growth),4) helps to decrease soil erosion,5) supplies plant nutrients (as it breaks down, it releases nutrients back into the soil),6) holds cation nutrients (positively charged ions which include most plant nutrients).
16Soil TerminologypH expression of both acidity and alkalinity on a scale whose values run from 0 to 14 with 7 representing neutrality, <7 represents acidity, and >7 represents alkalinitypH has a significant impact on the availability of soil nutrientspH pH objective for most ag cropspH: expression of both acidity and alkalinity on a scale whose values run from 0 to 14 with:7 representing neutrality,less than 7 represents acidity andgreater than 7 represents alkalinity.pH has a significant impact on the availability of plant soil nutrients.Most agricultural crops prefer a pH 6.5 for best growth.
17pH ScaleThe figure shows the break down of where acidity to alkalinity is on the pH scale. PH 7 is neutral.The figure shows the break down of where acidity to alkalinity is on the pH scale. PH 7 is neutral.
18pH Effect on Nutrient Availability This has a direct impact on plant health. For most agricultural crop recommendations, the goal is to have a 6.5 pH. At this pH most of the essential plant nutrients are available.This graphic shows how the major plant nutrients change in availability with the increase and decrease of pH.The wider the black band in this graphic, the more available the nutrient.Graphic shows how the major plant nutrients change in availability with the increase and decrease of pH.The wider the black band in this graphic, the more available the nutrient.This has a direct impact on plant health. For most agricultural crop recommendations, the goal is to have a 6.5 pH. At this pH most of the essential plant nutrients are available.
19pH Preferences by Plants As can be seen from the black bands, most plants prefer a pH between 5.5 and 7.0.This graphic shows the range in pH preferred by plants. This shows that it is important for producers to know the fertility and pH requirements of the plants they plan to grow.A pH below 5.5 is considered to be very acid and above 7.0 is alkaline.Graphic shows the range in pH preferred by plants. This shows that it is important for producers to know the fertility and pH requirements of the plants they plan to grow.As can be seen from the black bands, most plants prefer a pH between 5.5 and A pH below 5.5 is considered to be very acid and above 7.0 is alkaline..
20Limiting FactorsA layer which restricts the downward penetration of a plant’s root systemwill reduce growth in direct relationto the depth of the layer.On rare occasions, a limiting layer may increase site productivity, such as on sandy soils where the layer may retard leaching of nutrients and increase available moisture.RootSometimes a soil has a layer that can restrict the penetration of plant roots. This can limit the growth of a plant. This limiting layer can be man-made or naturally occurring. A man-made hard pan can develop at the bottom of a plow layer as a result of years of plowing. A look at the county Soil Survey Map can tell you if your soil has a naturally occurring limiting layer.Under some conditions, a limiting layer can be of benefit. For example, in a sandy soil leached plant nutrients would accumulate at the limiting layer where plant roots would be able to utilize these otherwise lost nutrients.
21SubsoilingSubsoilers have long shanks that physically dig down to break open the hard soil to form channels where plant roots can penetrate.There are farm implements available that can breakup soil hard pans and improve the crop production in otherwise limited soils.Subsoilers have long shanks that physically dig down to break open the hard soil to form channels where plant roots can penetrate.There are farm implements available that can breakup soil hard pans and improve the crop production in otherwise limited soils.
2216 Essential Elements (part 1) The primary elements are plant nutrients that are needed and most used by plants for growth. The primary nutrients can be found in commercial complete fertilizers as the fertilizer number reflects these three elements, i.ePrimary Nitrogen (N) Phosphorus (P) Potassium (K)Secondary Sulfur (S) Magnesium (Mg) Calcium (Ca)Secondary elements are the next most needed plant nutrients. Magnesium and calcium are obtained from liming materials. During the Industrial revolution, most of our sulfur came from air pollution (sulfur dioxide).There are three primary elements. They are nitrogen, phosphorus, and potassium. Primary elements are those plant nutrients that are needed and most used by plants for growth. Secondary elements are the next most needed plant nutrients. These include sulfur, magnesium, and calcium. The primary nutrients can be found in commercial complete fertilizers as the fertilizer number reflects these three elements, i.e Magnesium and calcium are obtained from liming materials. During the Industrial revolution, most of our sulfur came from air pollution (sulfur dioxide). In recent years, producers have had to routinely include supplemental sulfur to their crop fertility programs as the air around us becomes less contaminated with sulfur.In recent years, producers have had to routinely include supplemental sulfur to their crop fertility programs as the air around us becomes less contaminated with sulfur.
2316 Essential Elements (part 2) Micro-nutrients Iron (Fe) Manganese (Mn) Boron (B) Chlorine (Cl) Zinc (Zn) Copper (Cu) Molybdenum (Mo)Micronutrients are plant nutrients that are needed in only small amounts. These include iron, manganese, boron, chlorine, zinc, copper, and molybdenum. All 16 essential elements are important. A deficiency in any one of them will impact on plant growth.
2416 Essential Elements (part 3) The final three (3) essential elements to plant growth come mostly from air and water.They are: Carbon (C) Hydrogen (H) Oxygen (O)The final three- (3) essential elements to plant growth come mostly from air and water. They are carbon, hydrogen, and oxygen. Carbon in the form of carbon dioxide (CO2) and oxygen are found in abundance in the air. Water (H2O) is a source of hydrogen and oxygen.
25The Primary ElementsNitrogen: It gives plants their green color, promotes above ground growth, and regulates utilization of other elements.Phosphorus: It has favorable affect on- cell division stem strength- crop maturation root development- flowering/fruiting - disease resistanceNitrogen: It gives plants their green color, promotes above ground growth, and since it stimulates plant growth, it regulates the utilization of the other 15 essential elements.Phosphorus: It has a favorable affect on: cell division, stem strength, crop maturation, root development, flowering/fruiting, and disease resistance.
26The Primary Elements (con’t) Potassium (K) It is essential for starch formation and translocation of sugars. It is also essential to the development of chlorophyll. K helps plants to over-winter.Potassium: It is essential for starch formation and translocation of sugars. It is also essential to the development of chlorophyll. Potassium helps plants to over winter. For this reason, high ratios of potash (K2O) can be found in crop/plant winterizing fertilizers.
27What is the nutrient content of commercial fertilizers? Expressed as a percent called the “guaranteed analysis” or fertilizer grade.Nutrient content always appears in this order:% total nitrogen% available phosphate (P2O5), or phosphoric acid% soluble potash (K2O)The nutrient content of commercially available fertilizer is expressed as a percent called the guaranteed analysis or fertilizer grade. This always appears as % total nitrogen, % available phosphate, or phosphoric acid, and % soluble potash.
28The Fertilizer Number The fertilizer number refers to a ratio of N-P-K (1-2-1 ratio) has: 5% N 10% P205 5% K20 = 20%The other 80% of the material is called the carrier. This is typically some inert material.(2-1-1 ratio) (1-1-1 ratio)The fertilizer number refers to a ratio of nitrogen to phosphorus to potassium fertilizer is an example of a ratio fertilizer. The fertilizer number reflects the percentage of nutrients in the material fertilizer has a total of 20% nutrients, with the other 80% of the material being inert, or carrier material.
29What does a fertilizer guarantee mean? This bag contains: % nitrogen--10% phosphate--15% potash or lbs. nitrogen lbs. phosphate lbs. potashAg-Gro-Pro lbs.Using the analysis (grade) of the fertilizer and the total weight of the bag, the actual amount of plant nutrients in the bag can be easily calculated. For example, this 50 lb. bag of contains 5% nitrogen, 10% phosphate, and 15% potash. By multiplying the nutrient percentages times the total weight in the bag, we find that the bag contains 2.5 lbs. Of nitrogen, 5 lbs. Of phosphate, and 7.5 lbs. of potash. This means that the bag contains 15 lbs. of plant nutrients and 35 lbs. of inert ingredients.
30Common Fertilizers Urea 46 - 0 - 0 Ammonium nitrate 34 - 0 - 0 UANAmmonium sulfateDiammonium phosphateTriple superphosphateMuriate of potashSlide reflects a list of the most commonly used fertilizers in the region and their analyses. Many of these materials are custom mixed together to meet the specific fertility needs of a crop based on soil test results.
31Determining Fertilizer Need Production Goal: Total lb/A N - P - Ksoil reserve N –P - K crop residue Nmanure N - P - K______________Commercial fertilizer + lb/A N - P - KSlide reflects the basic outline of a nutrient management plan for crop production on a specific field. The primary nutrient requirements to meet the production goal will provide the amount of N-P-K needed to meet that goal. A soil test will provide the amount of soil reserves of nutrients, which can be subtracted from the total needed.Next, if any legumes such as clover were grown in the field the previous year, the residual nitrogen left in the field can be subtracted from the total needed.Finally, if any manure or biosolids are applied to the field, the nutrient value of the N-P-K in manure can be subtracted from the total.The net result of the amount of nutrients needed to meet the crop production goal can be supplied by commercial fertilizer. This process helps to avoid applying unnecessary nutrients, which impacts on the environment and also wastes the crop producer’s money.
32needs 60 lbs./A of potash (K2O) on his soybean crop Example: Calculating the Quantity of Commercial Fertilizer Required to meet a Nutrient RecommendationJasper Little Farm:needs 60 lbs./A of potash (K2O) on his soybean cropbroadcasts muriate of potash (0-0-60) pre-plantsee Example 4-1, p.18 in training guideThis example can be found on page 18 in the Nutrient Applicator Training Guide.
33Calculating Quantity of Commercial Fertilizer 1) RECORD recommended quantity of nutrient (see nutrient management plan).2) RECORD the percentage of nutrient in the preferred product, muriate of potash.3) CONVERT the percentage of nutrient to a decimal fraction by multiplying the % by .0160 lbs./AThis slide is a continuation of the previous example.60%60 x 0.01 = .60
34Calculating the Quantity of Calculating the Quantity of Commercial Fertilizer CALCULATE the quantity of muriate of potash required in lbs./A: divide the recommended quantity of nutrient by the nutrient content expressed as a decimal fraction.This slide concludes the example used in the two previous slides.60 lbs./A ÷ 0.60 = 100 lbs./ALittle needs 100 lbs. of muriate of potash to supply 60 lbs. of potash. Done!
35Determining Production Goal Cropping historySoil Survey Map/Soil Capability ChartInvestigate species/variety potential - other growers field days private and university trial resultsFSA recordsExperimentationOne of the most important factors in developing an accurate nutrient management plan is determining realistic production goals. Often producers strive for crop yield goals that they would like to obtain, but in reality can never achieve due to factors beyond their control. This wastes resources. Realistic crop yields can be determined by1) looking at the crop production history of the field,2) reviewing the Soil Survey Map and Soil Capability Chart (these will provide soil engineer’s assessments at the potential production ability of the soil in the field),3) investigate how the crop species and varieties you want to grow have done for other growers in your area and in research and demonstration plots,4) Farm Service Agency (FSA) keeps records on the yields of some crops that are reported to them by producers, and5) your experimentation with a small, limited planting of a new crop before committing to a large planting will provide valuable experience on how to grow the crop and what kind of yield to expect.
36Determining Yield Goal Take the average yield for typical years that a crop is grown in a certain field.Estimate yields goal by averaging the yield from the best 3 of 5 growing seasons.When actual yield data is not available, estimated yields for the soil type in the field can be found in “MASCAP”.MASCAP MARYLAND’S AGRONOMIC SOIL CAPABILITY ASSESSMENT PROGRAMVa. A. Bandel, and E.A. HegerAgronomy Department Cooperative Extension Service University of MarylandSeptember 1994Actual crop yields from the farm are best for setting yield estimates. Taking the average yield for typical crop production years grown in a certain field can provide a good estimate of yield. Taking an average of three of the top five growing seasons can make another yield estimate. When actual yield data is not available, the MASCAP chart is available at the county Soil Conservation District office. This can provide an estimate based on the farm’s soil types.
37Soil Reserve Soil test - university lab - private labs Frequency of testing depends on crop and managementTypical test looks at P, K, Ca, Mg, O.M., and pH. Minors are as needed.Keeping an eye on the nutrients in the soil reserve is essential to maintaining good soil fertility. Soil testing for these nutrients is simple and economical. They can be obtained through private industry and university labs.Soil tests should be done annually for high production crops like alfalfa and annual crops. Permanent pastures, grass and mixed hay fields can be soil tested every three to five years once the fertility level for best plant growth has been met.
38Fig. 1-1: Phosphate Recommendation (lbs/A) as a function of soil fertility level (FIV-P) for corn grain (yield goal-150 bu/A)# P205/AThis graph shows how the recommended rate of a plant nutrient (Phosphate) will increase or decrease depending on the level of that nutrient found in the soil test. This is why soil testing for plant nutrients is important. This helps to avoid over applying nutrients, which can harm the environment and waste money. Also, soil testing helps to avoid crop losses from plant nutrient deficiencies.ExcessiveLowMediumOptimum
39Crop Residue Benefits left by a previous crop or cover crop Previous crops leave little unless it was a leguminous cropLeguminous crops leave nitrogenThe amount of N left depends on the species of legume and the stand density and maturity.Cover crops are not harvested and will recover nutrients otherwise lost.Plant fertility benefits left in the soil by a previous crop is often overlooked and not taken advantage of by producers.Leguminous crops provide the most benefit to following crops since they “fix” nitrogen and leave it in the soil for following crops to utilize. Leguminous crops can be used as crops grown for either cash, or animal feed, or as a cover crop.
40ManureAnalysis is available from the University of Maryland’s Soil Testing Laboratory.Manure, biosolids (sludge), and composts contribute to the pool of plant nutrients in the soil. As an organic source, the nutrients are in various stages of decomposition. This will result in a long, slow release of these nutrients. These materials can be analyzed to obtain the amount of nutrients they contain. This plus accurate spreading over the field is essential to the best use of these important fertility resources.
41How much of the nitrogen in manure is plant-available? It depends on:* the nitrogen content* animal species* incorporation practicesThe answer to this question depends on the nitrogen content of the manure, the animal species, and if the manure was incorporated into the soil or surface applied.
42Figure 2- 3b. Distribution of organic nitrogen & ammonium nitrogen in dairy manure This pie chart shows that this example of one ton of dairy manure has a total of 12 lbs. of nitrogen. Of this 12 pounds, nine pounds of it is in the form of organic nitrogen and 3 pounds is in the form of ammonium nitrogen.This dairy manure contains 12 pounds of total nitrogen per ton.
43Available Organic Nitrogen Only part of the nitrogen in manure becomes plant-available -- through the process of mineralization -- the year it’s applied.Only part of the nitrogen in manure becomes plant-available in the year of application. The rest of the nitrogen in the manure becomes slowly available through a process called mineralization over the next couple of years. Mineralization involves the breaking down of the organic matter in the manure by microorganisms to a point where the nitrogen is rendered into a form that plants can use.
44Nitrogen “Credits”Organic nitrogen in organic sources continues to break down or mineralize for several years after application.The largest proportion of this organic nitrogen breaks down and becomes available in the year of application.Organic sources include manure, biosolids (sludge), and composts.Usually about one-half of the total nitrogen becomes plant-available in the first year. Through mineralization, the rest of the nitrogen becomes plant-available in progressively lower amounts over the next two to three years. Organic sources of nitrogen include manure, biosolids (sludge), and composts.
45Nitrogen “Credits”Progressively smaller amounts of the organic nitrogen break down and become available in the subsequent years.Credit needs to be given to this available nitrogen from previously applied manure to the current year’s nitrogen recommendation.Since all of the nitrogen in manure does not become plant-available in the year that it is applied, credit needs to be given to the nitrogen that becomes available over the following two years. This helps to prevent the application of excessive amounts of nitrogen.
46Figure 2- 4b: Distribution of Available Nitrogen from Organic and Ammonium Nitrogen Components in Dairy Manure0.6 lb2.4 lb6 lb3 lbThis pie chart shows that of the 12 pounds of total nitrogen in this ton of dairy manure, 5.4 pounds of it is plant-available. This includes 3 lbs. of organic nitrogen and 2.4 lbs. of ammonium nitrogen. The balance of the nitrogen in this manure will become available over time through mineralization.This dairy manure contains 12 pounds of total nitrogen and pounds of available nitrogen per ton
47A funny slide to breakup the class A funny slide to breakup the class. This could be an Iraqi surface to air missile.Don’t Overload!A funny slide to breakup the class. This could be an Iraqi surface to air missile.
48Manure Mineralization Factors Vary by animal species.See Table 2-1 in the Nutrient Applicator Guide.The mineralization rate of manure varies between animal species. A table explaining these differences can be found in the Nutrient Applicator Guide on page 10.The mineralization rate of manure varies between animal species. A table explaining these differences can be found in the Nutrient Applicator Guide on page 10.
49Available Ammonium Nitrogen NH4 is a plant-available form of N.When manure is left on the soil surface after application, it can be lost through the process of volatilization Nitrogen LossAmmonium is a plant-available form of nitrogen found in manure. When left on the soil surface, it can be lost through volatilization. When you can smell manure that has been applied to a field, it is losing nitrogen through volatilization. The odor of manure is largely nitrogen-based. Incorporating manure into the soil reduces the odor coming off of the field and traps the volatile nitrogen in the soil preventing its loss.
50Estimated Manure Values Dairy (fresh, spread daily) 89% moist (lb/T)Dairy (stored outside, leachate lost) 87% moist (lb/T)Poultry (layer stored in pit) 65% moist (lb/T)Swine (storage tank beneath slotted floor) 95% moist (lb/T)Beef (bedded manure pack under roof) 80% moist (lb/T)Ammonium is a plant-available form of nitrogen found in manure. When left on the soil surface, it can be lost through volatilization. When you can smell manure that has been applied to a field, it is losing nitrogen through volatilization. The odor of manure is largely nitrogen-based. Incorporating manure into the soil reduces the odor coming off of the field and traps the volatile nitrogen in the soil preventing its loss.
51PAN content of semi-solid dairy manure is 6 lbs./T Example: Calculating Quantity of Dairy Manure to Meet Crop Nutrient Recommendation Ralph Gonzales FarmPAN content of semi-solid dairy manure is 6 lbs./Twants to supply the N for his corn cropyield goal is 120 bu/Aincorporates the manure the same day as applicationsee Example 4-2, p.19 in training guideThis example can be found on page 19 in the Nutrient Applicator Training Guide. This example helps to show how one can use the plant available nitrogen content of a manure to calculate the amount of manure to use to meet plant nutrient requirements.
52Calculating Quantity of Dairy Manure to Meet Recommendation Note: The nitrogen recommendation for corn grain is 1 lb./A of PAN per bushel of yield.1) RECORD nitrogen recommendation (lbs./A) from the nutrient management plan.2) RECORD PAN of manure (lbs./T)This slide continues with the calculation of the previous slide.120 lbs./A6 lbs./T
53Calculating Quantity of Dairy Manure to Meet Recommendation CALCULATE the quantity of manure required in T/A: divide the nitrogen recommendation by the PAN of manure.120 lbs./A ÷ 6 = 20 T/AThis slide completes the calculation of the previous two slides.Twenty tons of a dairy manure with this PAN are needed to provide 120 lbs./A of PAN Done!
54Use of Raw Manure Heavy applications can throw off nutrient balance Excess available N can lead to excessive growth and nitrate buildup in plantPlants with high nitrates do not store as well and attract insectsNitrogen and phosphorus are pollutantsWeed seeds pass through animalsBecause of all of the soluble, readily available nutrients in fresh manure, its application to a field can throw off the nutrient balance of a field. The excess available nitrogen in it can lead to excessive plant growth and a nitrate build up in the plant. Excess nitrate build up in plants can lead to insect pest problems, poor storage quality, and toxicity as a forage plant. Excess soluble forms of nitrogen and phosphorus can move off of the field and pollute surface waters. Composting manure can help to reduce the impact of these nutrients on the field and also kill some of the weed seeds in the manure that would otherwise germinate in the field.
55Often Forgotten Sources of N Carryover from past manure/biosolidsCover crops ( fixed & recycled N)N released from soil organic matter (40-80 lb/A)Nitrates in rain & irrigation waterWeeds, plowed down have slow-release N, 85 lb/T pigweed, 80 lb/T lambsquarterCrop residues, humus, bedding, and compostsNitrogen is a dynamic element in the environment around the farm. Plants can receive nitrogen from many other sources in addition to the fertilizer applications by the producer. Some of these often over-looked sources include: 1) carryover from previous manure/biosolids applications (As discussed earlier, the organic material will break down over a period of three years releasing nutrients.), 2) cover crops (As discussed earlier, legumes leave behind nitrogen in the soil. Also, deep-rooted cover crops can bring up nutrients from deep in the soil for use by following crops once the cover crop decomposes. These nutrients would otherwise be lost.), 3) Nitrogen is constantly being released from decomposing organic matter; as much as lb./A is released annually.), 4) The nitrogen released from plowed down, decomposed weeds can be as much as 85 lb./A.), 5) Crop residues, humus, bedding, and composts all contain organic nitrogen that can benefit crops.
56(commercial fertilizers) ComponentInput to soilLoss from soilThe Nitrogen CycleAtmosphericnitrogenAtmosphericfixationand depositionIndustrial fixation(commercial fertilizers)CropharvestAnimalmanuresand biosolidsVolatilizationPlantresiduesRunoff anderosionBiologicalfixation bylegume plantsPlantuptakeThis diagram shows the nitrogen cycle and how dynamic it is in the environment. It is constantly changing forms. This makes it difficult to measure in the soil.DenitrificationOrganicnitrogenNitrate(NO3)Ammonium(NH4)-Immobilization+LeachingMineralization
57The Phosphorus Cycle Crop Atmospheric harvest deposition Animal ComponentInput to soilLoss from soilThe Phosphorus CycleCropharvestAtmosphericdepositionAnimalmanuresand biosolidsMineralfertilizersPlantresiduesRunoff anderosionPrimaryminerals(apatite)Organic phosphorusMicrobialPlant residueHumusPlantuptakeMineralsurfaces(clays, Fe andAl oxides,carbonates)WeatheringThe phosphorus cycle is not as complicated as nitrogen, but it is not simple either. There are many factors at work in the soil that directly impact on its plant-availability.AdsorptionImmobilizationMineralizationSoil solutionphosphorusHPO4-2H2PO4-1DesorptionSecondarycompounds(CaP, FeP, MnP, AlP)DissolutionLeaching(usually minor)Precipitation
58The Potassium Cycle Animal manures Crop and biosolids harvest Plant ComponentInput to soilLoss from soilThe Potassium CycleAnimalmanuresand biosolidsCropharvestPlantresiduesMineralfertilizersRunoff anderosionExchangeablepotassiumPlantuptakeThe potassium cycle shows that, by nitrogen and phosphorus cycle standards, it has a little simpler life in the environment.Soil solutionpotassium (K+)FixedpotassiumMineralpotassiumLeaching
59The Sulfur Cycle - Atmospheric sulfur Volatilization Atmospheric ComponentInput to soilLoss from soilThe Sulfur CycleAtmosphericsulfurVolatilizationAtmosphericdepositionCropharvestSO2 gasMineralfertilizersPlantresiduesAnimalmanuresand biosolidsElementalsulfurRunoff anderosionAbsorbed ormineral sulfurPlantuptakeThe sulfur cycle shows that this is another plant nutrient that has a complex life in the environment. For this reason, nitrogen and sulfur are two plant nutrients that are difficult to soil test for plant available nutrients. At one time, air pollution (sulfur dioxide) was a good source of plant available sulfur to farm crops.OxidationOrganicsulfurBacterial oxidationReduced sulfurImmobilizationSulfateSulfur(SO4)Bacterial reductionMineralization-Leaching
60Fertilizer Application Terms Broadcast fertilizer is applied uniformly to entire field before crop emergesTopdress fertilizer is applied uniformly to entire field after crop emergesPlowed down or tilled in - fertilizer is applied to field then is tilled in with a disk or a plowCrop producers need to be familiar with the terminology associated with the application of fertilizer. These are:Broadcast: fertilizer applied uniformly to entire field before the crop emerges.Topdress: fertilizer is applied uniformly to entire field after the crop emerges.Plowed down: fertilizer is applied to the field then is tilled in with a disk or plow.
61Fertilizer Application Terms Banded fertilizer is applied directly over the top of the crop row, generally before the crop emerges, omitting the area between the rowsSide-dressed fertilizer is applied directly to growing crop, generally in a band at the base of the plantBanded: fertilizer is applied directly over the top of the crop row, generally before the crop emerges, omitting the area between the rows.Side-dresses: fertilizer is applied directly to a growing crop, generally in a band at the base of the plant.
62Calibrating Nutrient Application Equipment Calibration is a way to set your application equipment to apply material uniformly at the desired rate.It insures application of the required amount of nutrients without over-fertilizing.Two common methods are used: - weight-area method - load-area methodCalibration is how we insure that sprayers and spreaders apply the proper amount of material in the field. Incorrect applications of manure or fertilizer can adversely affect the yield potential of a crop. Low applications will restrict crop yield and excessive applications will waste money and can harm the environment. The two commonly used methods of calibrating spreaders are the weight-area method and the load-area method.
63Basics of Calibration L e n Area = Length x Width g t h L e n g t h Determining the square feet in an area is basic to the calibration of farm equipment. The size of an area can be determined by multiplying length X width.Area = Length x WidthLengthLengthDetermining the square feet in an area is basic to the calibration of farm equipment. The size of an area can be determined by multiplying length X width.WidthWidth
64How to Calibrate Nutrient Application Equipment Measure the actual rate of application.Compare actual application rate to the recommended application rate.If the application rate is substantially greater or less than the recommended rate, try: changing equipment settings, or - changing ground speed of the tractorCalibrating a spreader basically involves measuring the actual rate of application and then comparing it to the recommended application rate. If the actual rate is substantially more or less than the recommended rate, try changing equipment settings, or changing the ground speed of the tractor.
65Load-Area Method Know: capacity of the spreader size of the area where manure is spreadApply nutrient supplying material, then measure area of application. Project rate of application to a per-acre basis.The load-area method of calibration is described on page 22 in the Nutrient Applicators Training Guide. Essentially in the method, the applicator needs to know the capacity of the spreader and the size of the area applied. By measuring the amount of material applied in this known area, the rate per acre of material can be calculated. The amount of total material applied is based on the weight or volume of material that was applied out of the spreader into the calibration area. An acre is equal to 43,560 square feet.
66Weight-Area Method for Manure 1. Arrange at least 3 plastic sheets in the center of the spreader’s path.2. Drive the spreader over the center of the sheets at a known speed with specific equipment settings.3. Collect & weigh the manure on each sheet.4. Average the quantity applied to the sheets and project to T/A.In the weight-area method, it differs from the load-area method in that the applicator has to collect material spread in the field. This can be done with pans, or plastic sheets. The applicator drives the tractor over the collection site then collects/weighs the samples. The average quantity of material collected is calculated out to a tons/acre rate. This is then compared to the recommended rate. The weight-area method is described on page 22 of the Nutrient Applicators Training Guide.
67Weight-Area MethodWorks well with calibrating fertilizer spreaders and planters.Works well with calibrating both dry and liquid manure spreaders.- pans can be used to catch liquid manure- plastic sheets can be used to catch dry manureThe weight-area method works well with calibrating both fertilizer spreaders and planters. This method can be used for both liquid and dry manure spreaders. Pans can be used to catch liquid manure and plastic sheets can be used to catch dry manure.
68Basics of Calibration Using Sheets and Pans This diagram shows how pans and sheets can be arranged in a field to calibrate a spreader.123Spread manureThis diagram shows how pans and sheets can be arranged in a field to calibrate a spreader.279Spread manure15834610
69Refer to your “Nutrient Applicator’s Training Guide “ for additional help The Nutrient Applicators Training Guide has detailed examples of how to properly calibrate nutrient application equipment.
70Let’s take a quick look at some other materials we apply to our soils. This is a lead-in slide to a discussion on liming materials and compost.
71Limestone Supplies calcium and magnesium Mined calcium carbonate is the principle liming material, typically 50% oxidesCaCO3 equivalent is the basis for liming material recommendation ratesComes in various forms and gradesLimestone supplies calcium and magnesium. Mined calcium carbonate (CaCO3) is typically 50% oxides, which is that portion of the liming material that reacts in the soil to raise the pH. The other 50% of the material is inert. CaCO3 equivalent is the basis used for measuring the neutralizing capacity of all liming materials. Limestone comes in many different forms and grades.
72Comparing Liming Materials Effective Neutralizing ValueE.N.V.This is a comparative value that refers to the ability of a liming material to modify soil pH within a year.Reference Standard:Calcium carbonate (CaCO3)E.N.V.= 100Effective Neutralizing Value (E.N.V.) is a comparative value that refers to the ability of a liming material to modify soil pH within a year. The reference standard is calcium carbonate (CaCO3), where E.N.V. = This means that liming materials are compared (greater than or less than) to the neutralizing ability of calcium carbonate. E.N.V. can be found on the labels of liming materials and fertilizer as an indicator of the products impact on soil pH.This means that liming materials are compared (greater than or less than) to the neutralizing ability of calcium carbonate. E.N.V. can be found on the labels of liming materials and fertilizer as an indicator of the products impact on soil pH.
73Limestone Mesh size determines how quickly it reacts in the soil Good quality ag lime is typically 80% mesh and 20% 40 meshGround dolomite (dolomitic lime) is over 10% magnesium; it is a good source of Mg when neededThe liming material label (or tag) will tell you the mesh size of the material. This will tell you how quickly the limestone will react in the soil. Good quality Ag lime will be 80% mesh and 20% 40 mesh. The mesh portion of the limestone will react almost immediately in the soil, while the 40-mesh portion will take 6 months to a year. This will provide a rapid and a slow release of the lime. Most Ag lime is only 1-2% magnesium oxide (MgO). This is usually fine for most soils. However there are soils that need more magnesium. In this situation, Dolomitic limestone can be applied. Ground Dolomite contains over 10% magnesium.
74Other Liming Agents These are typically industrial byproducts These include stack dust, sludge lime, and river mudDomino Sugar lime is a new sourceSolubility and % oxides vary, so get an analysisThese contain mostly Ca and traces of other elements and materialsThere are other liming agents available besides Ag lime. These materials are typically industrial byproducts. These include stack dust, sludge lime, river mud, and sugar lime. These materials usually have very soluble, rapid forms of calcium (CaO) and traces of other elements. Most of these materials work very quickly. Their percent of oxides can vary; so always ask to see an analysis of the material before calculating how much you need. These materials are much cheaper than Ag lime, but can be hard to apply.
75Liming Recommendations Know the analysis, especially % oxides -Application rate is based on lb/A oxides% calcium and magnesium - may not need additional MgOxide form of calcium (CaO) is readily availableMesh size of carbonate form of Ca (CaCO3 ) reflects its availability smaller particles work fasterIt is essential that you know the analysis of the liming material, especially the percent oxides. The amount of material you apply will be based on your soil pH and the percent oxides of the liming material. It is not necessary to apply high magnesium lime to soils that do not need the extra magnesium. This wastes money and does not benefit the nutrient balance in the soil.
76Liming NotesLimestone recommendations are based on raising the pH of the plow layer (top 7-9”) to 6.5; except for special crops; i.e. alfalfa.Limited to 1,500 lb/A oxides/year when not incorporating; i.e. pasturesAvoid applying liming products and fertilizer at, or around the same time.Liming materials laying on the surface will neutralize pesticides.Liming material recommendations are typically based on raising the pH of the plow layer (top 9 inches of the soil) to 6.5; except for those crops requiring a higher or lower pH. In situations where the soil cannot be tilled, such as pastures and no-till crops, the liming material is surface applied annually at no more than 1,500 lb. per acre of oxides until the requirement is met. Caution should be taken when applying liming materials in or around those times that you are planning to apply nitrogen-based fertilizer, or pesticides. Limestone can react with ammonium forms of nitrogen and cause it to volatilize, and limestone will neutralize pesticides. Limestone will free up herbicides tied-up in the soil, which could injure newly germinating seedlings sensitive to that herbicide. Liming a few months in advance of seeding will help to avoid this problem.
77Compost Decomposed Plant & animal Matter When correctly done:- pH is near neutral- C:N ratio is 15:1- Majority of weed seeds & disease organisms are dead- Offers a well balanced slow release supply of nutrients- As much as 1/4 of compost weight is microbes (dead & alive)When compost is made properly it is near pH 7 (neutral), has a carbon: nitrogen ratio of about 15:1, most of the weed seeds and disease organisms are dead, contains a well balanced supply of slow release plant nutrients, and has as much as one-quarter of its weight in micro-organisms (dead and alive).
78Principles of Composting Best composts come from piles with the highest microbial activityTemperature is easiest sign of microbial activityGood composts heat to approximately F within the first 3 or 4 daysThe best composts come from piles with the highest microbial activity. Temperature is the easiest way to judge the level of microbial activity. Good composts heat to approximately F within the first 3 or 4 days.
79Principles of Composting Small particle size makes a greater surface area available to microbes - particles that are too small however can pack a pileAdequate volume, or size of pile keeps it from cooling too quickly - piles 4 x 4 x 4 ft. do wellThe size of the particles in the compost pile is important to its success. Small particle size provides greater surface area availability to microbes, however if the particles are too small, they will pack too tightly and exclude the air necessary to good heating. Adequate volume is important as well. Piles need to be big enough to keep from cooling too rapidly. Piles 4x4x4 ft. do well.
80Unfinished Composts Can hurt crops Chemicals formed in process are toxic to plantsN can be tied upGood composts take monthsMoisture must be adequate ( %) similar to a squeezed spongeC:N ratio in initial pile should be 30:1Improperly made or unfinished composts can be harmful to plants. They can contain toxic chemicals formed in the process, or the valuable nutrient nitrogen can be tied-up. Good composts take months to make and will have the moisture content similar to that of a squeezed sponge. The C:N ratio in the initial startup of the pile should be 30:1.
81Common C:N Ratios Undisturbed top soil 10:1 Alfalfa 13:1 Rotted barnyard manure 20:1Corn stalks 60:1Small grain straw 80:1Oak :1Spruce :1This slide shows the carbon: nitrogen ratios of some familiar materials around the farm. The higher the C:N ratio, the longer it takes to decompose, or compost.
82Compost Problem Solving Bad Odor- not enough air- turn the pile more frequentlyCenter of pile too dry- not enough water- moisten while turningBad odor: not enough air, so turn the pile more frequentlyCenter of pile too dry: not enough water, so moisten while turning
83Compost Problem Solving Pile is damp & warm in center, but nowhere else pile is too small collect more material and mix the old ingredients into a new pilePile is damp and sweet smelling, but will not heat up lack of nitrogen mix in N-rich material like fresh grass, manure, or ureaPile is damp &warm in center, but nowhere else: pile is too small, so collect more material and mix the old ingredients into a new pile.Pile is damp and sweet smelling but will not heat up: lack of nitrogen, so mix in N-rich materials like fresh grass, manure, or urea.
84Crop Rotation and Cover Crops Benefits crop fertility fixed and recaptured nutrientsBenefits soil structure (tilth) - cover crops add organic matter - variability in root growth improves soil pores and water penetrationPest management breaks the parasite life cycleHarvest vs. cover crop is the decisionCrop rotation provides nutrients to plants by recapturing nutrients that having moved down the soil below the root zone of most crop roots. Rotating to a deeper-rooted crop helps to capture these nutrients before they are lost. This helps the environment by preventing these nutrients from getting into groundwater. Rotating to leguminous crops helps plant fertility, since legumes fix nitrogen that benefits following crops. Using cover crops (crops not harvested) in a rotation provides benefits directly to the soil by improving soil tilth and water infiltration, and organic matter. Crop rotation is one of the best methods of pest management, as pest populations can often be kept low through alternating different species of plants. The decision to use a cover crop in the crop rotation system is difficult, since the cover crop is not harvested and there is no direct financial return.
85Some Parting AdviceSeek help when you are not sure about what you are doing. There are a lot of resources out there for you.Don’t be like the old farmer who told the County Agent that he did not need any advice. He told the Agent that he has already worn out two farms and that he had his own way of doing things.Be sure to seek help when you are not sure about what you are doing. There are a lot of resources around to help you. Don’t be like the old farmer who told the County Agent that he didn’t need any advice. He told the Agent he has already worn out two farms and that he has his own way of doing things.