Presentation on theme: "MANAJEMEN NITROGEN TANAMAN JAGUNG Bahan Kajian MK. Manajemen Kesuburan Tanah Smno.agroekotek.fpub.sept2013."— Presentation transcript:
MANAJEMEN NITROGEN TANAMAN JAGUNG Bahan Kajian MK. Manajemen Kesuburan Tanah Smno.agroekotek.fpub.sept2013
Tanaman jagung memerlukan sejumlah besar nitrogen Proper nitrogen fertilizer application Good nitrogen management is essential for protecting groundwater quality. Proper nitrogen management includes managing nitrogen rate, source, timing, and placement. The primary goal of nitrogen best management practices is attaining high nitrogen use efficiency. This assures the most effective use of nitrogen fertilizer.
Nitrogen Rate Yield Economic Optimal N Rate (EONR) The sufficiency range is the nutrient level at which the plant has enough nutrients to function and develop properly, but not so much that it is poisoned. This is reported as "medium" or "high" on soil tests.
Nitrogen Rate Yield Economic Optimal N Rate (EONR)
Oran00 Rep1 Block N rate (kg ha -1 ) Yield (Mg ha -1 ) N opt Oran00 Rep3 Block N rate (kg ha -1 ) Yield (Mg ha -1 ) N opt Economic Optimum Nitrogen Rate
1. EONR prediction is not easily accomplished, and is more of a challenge in rainfed environments. 2. If one could reliably predict yield, this factor alone does not do a good job of predicting EONR. 3. In 2004 and averaged over all sites, we achieved ~$5/acre more profit when using the sensors when compared to the farmers single blanket rate. (average of 30 lbs/acre less N). 4. Data needs to be collected to test current and yet-to-be developed algorithms.
Research supported in part by the USDA- NRI, IFAFS, and CIG Grant Programs. Assistance also given by OSU, NTech, and Holland Scientific Instruments.
The corn N recommendations are based on: - Yield potential - soil type and drainage - Soil N supply - soil type and drainage - N fertilizer uptake efficiency - soil type and drainage - N credits from sods - % legume/grass in the sod - N credits from manure - application method + timing N Recommendation for corn
(yield potential * 1.2) – soil N – sod N (yield potential * 1.2) – soil N – sod N N requirement = N requirement = (fertilizer efficiency/100) (fertilizer efficiency/100) in lbs N/acre in % in bushels/acre = soil series specific Cornell Corn N Recommendations - soybean N or manure N credits
Loss-on-ignition (g kg -1 ) Initial Field Calibration
Factors relating to BMPs for N 1.Cropping systems 2.N rate applied 3.Time of application 4.Nitrification inhibitors 5.N source 6.Tillage 7.Cover crops Established Gliricidia-maize intercropping system in Southern Malawi. Photo: T. Breedy
CROPPING SYSTEMS brazilian-cerrados
Effect of CROPPING SYSTEM on drainage volume, NO 3 -N concentration, and N loss in subsurface tile drainage during a 4-yr period ( ) in MN. CroppingTotalNitrate-N SystemdischargeConc.Loss Inches ppmlb/A Cont. Corn Corn – Soybean Soybean – C Alfalfa CRP
Nitrate losses in tile drainage water from soil mineralization. Dry years Established grass
Cropping system has greater effect on hydrology and nitrate losses than any other management factor! Preventive Management Cumulative Nitrogen Uptake Across the Growing Season
RATE OF APPLICATION Good nitrogen management requires understanding: 1.How nitrogen is used by the crop 2.When nitrogen is used by the crop 3.What environmental influences affect the use of soil and fertilizer nitrogen by the growing crop 4.How management of nitrogen and irrigation water affect the leaching of residual nitrate, which eventually affects water quality
Continuous Corn, 2001–03 Olmsted Co.
Effect of N rate for corn after soybean on NO 3 -N concentrations in tile drainage water in 2001.
Effect of N rate on yield of corn after soybean, net return to fertilizer N, and nitrate-N concentration in tile drainage at Waseca (2000–2003). N Treatment4-Yr YieldNet4-Yr FW TimeRateN-ServeAvg.ReturnNO 3 -N conc. lb /Abu/A$/A/Yrmg/L Fall 80Yes Spr.120No
Effect of N rate applied for corn in 2003 on nitrate-N concentration and loss in tile drainage during May– September 2004 from soybeans at Waseca. NFW Nitrate-NNitrate-N Rate.ConcentrationLoss Lb/Amg/LLb/A
Conclusion 1.Corn yields were increased 5% and nitrate losses in drainage were reduced by 27% when reducing the N application rate from 160 lb/A applied in the fall to the recommended 120-lb rate applied in the spring. 2.Reducing the N rate from 120 lb/A to 80 lb/A reduced yield by 17% and nitrate loss by 13%. 3.Forty-six percent of the nitrate lost in tile drainage from a corn-soybean rotation was lost in the year soybeans were grown.
TIME OF N APPLICATION Maximum nitrogen uptake occurs in periods of maximum growth (in corn roughly between vegetative growth stages V9 and V18, or from hip-high to just before tasseling). Risk of N loss is low during this period. Credit: Iowa State University Extension.
Effect of time of N application and N-Serve on corn yields after soybean from 1987–2001 at Waseca. Time of N Application ParameterFallFall+N-ServeSpring 15-Yr Avg. Yield (bu/A) Yr Avg. Economic return over fall N ($/A/yr) * ---$9.30$ Yr Avg. Yield (bu/A) ** Yr Avg. Economic return over fall N ($/A/yr) * ---$22.50$51.00 * Corn = $2.00/bu; N = $0.25/lb N ** Seven years when statistically significant differences occurred.
Nitrate-N concentration in tile drainage from a corn-soybean rotation as influenced by time of N application and N-Serve at Waseca. N Treatment Time of applicationN-ServeNitrate-N Conc.* -- mg/L -- FallNo14.1 FallYes12.2 SpringNo12.0 * 10-cycle ( ) rotation average.
1999 tile water NO 3 -N loading at Waseca vs. NO 3 -N concentrations in the Le Sueur River 2.3 miles from Mankato.
Conclusion Compared to late fall N application without N-Serve over the 15-year period: –Corn yields were increased 9 and 12 bu/A/yr (6 and 8%) by either fall N+N-Serve or spring preplant N, respectively. –Nitrate losses were decreased 14 and 15% by either fall N+N-Serve or spring preplant N, respectively.
Proposed BMPs for South-Central MN Recommended –Spring preplant or split applications of ammonia, urea, or UAN are highly recommended. –Incorporate broadcast urea or preplant UAN within three days. –Apply sidedress application before corn is 12 high. –Inject or incorporate sidedress applications of urea or UAN to a minimum depth of 4 inches.
Proposed BMPs for South-Central MN. Recommended, but with greater risk –Fall application of AA + N-Serve after soil temperature at 6-inch depth is below 50° F. –Side dressing all N before corn is 12 inches high. Not recommended –Fall application of urea, UAN, or anhydrous ammonia without N-Serve
Economic Nitrogen Management for CornNEW MSU N Recommendations
How much is enough? Old vs. new recommendations… Yield vs. Economic Return – Old: 1.2 lbs per bushel This only applies within yield potential of soil – New: Based on economic return This only applies within yield potential of soil Use previous crop in association with field history (low – medium – high – very high)
Definitions MRTN – maximum return to N EONR – economic optimum N rate N:Corn Price Ratio Corn Yields – 5 year averages – soil productivity (disregard unusual his or los) – Low: Average yield, <120 bu/a – Med: Average yield, 121 – 150 bu/a – High: Average yield, 151 – 180 bu/a – Very High: Over 181 bu/a
Response Data Model Fit Yield (bu/acre) N rate (lb/acre) OptimumMaximum
Critical value or range indicates the soil or tissue content below which the plant most likely is deficient in that specific nutrient and production could be enhanced by addition of the nutrient. Below that critical value, the nutrient levels are below optimum.
Luxury consumption occurs when soil nutrient levels are above optimum and plants take up more of a nutrient than needed for functioning and production. Potassium (K) is commonly taken up in excess.
How much is right? National Corn Growers Contest (NCGA): 10 separate yield checks averaged: – lbs of N/acre ( ) – Average yield = bu/acre ( ) –.76# N/bu ( ) Was it economical???? It depends…………
Key points… Determine soil productivity…a 5 year history. Determine N:Corn price ratio Evaluate crop conditions, and weather at the time of maximum N application. – This could be at planting or at sidedress time.
Criteria for Soil Productivity or Yield Potential Grouping 1.Low: 120 bu/a 2.Medium:121 – 150 bu/a 3.High:151 – 180 bu/a 4.Very High: 181 bu/a 5. 5 year running average!
Soil Yield Potential Qualitative assessment of soil productivity – Group soils with similar N response Tiled, non-tiled, high OM, etc. – Do Not use yield estimate to calculate N rate Based on soil series description Look at: – Water holding capacity – Drainage class – Depth of root zone – Length of growing season (> or < 2300 GDD)
N response functions Corn following Corn
Michigan MRTN Recommendation Version 1.0: Jan., 2008 Yield Potential Previous Crop Medium/Low Rate Range Corn Soybean Very High/High Corn Soybean N:Corn Price Ratio Suggested N rate – lbs N/acre Range: Approximates ± $1.00 of the Maximum Return to N (MRTN) rate.
Example # 1 1.Heavy clay soils 2.Non-tiled bu. average 4.Corn price $ N price (28%) $385/T 6.Previous crop - soybeans N:Corn Ratio =.22 Crop condition – excellent Soil Moisture – excellent Population 32,000/a Recommendation: 80 Lbs. added N/a range 65 – 95 lbs/a
Example # 2 1.Sandy loam soils 2.Tiled bu. average 4.Corn price $ N price (28%) $365/T 6.Previous crop soybeans 1.N:Corn Ratio =.16 2.Crop conditions – excellent 3.Population – 32,000 4.Soil moisture – very good 5.Recommendations: 105 lbs. added N range of lbs/a