Fertilizers and Tillage PLS 38609/23/05 Outline of topics: I. Land preparation II. Tillage systems III. Tillage implements

Fertilizers and Tillage PLS /23/05 p. 2 Land preparation Virgin land must be cleared by removing vegetation. Terrain modification can be undertaken on new land: 1. Leveling- for surface drainage, irrigation installation 2. Terracing- for steep slopes 3. To correct drainage problems

Fertilizers and Tillage PLS /23/05 p. 3 Purpose of tillage practices: 1. Land leveling 2. Seed bed preparation tilth- physical condition of a soil as related to its ease of tillage, fitness as a seedbed, and suitability to support crop growth. 3. Incorporating organic matter and other amendments 4. Weed control

Fertilizers and Tillage PLS /23/05 p. 4 Purpose of tillage practices, continued 5. Improve soil physical conditions 6. Erosion control 7. Shaping soil (raised beds, furrows, etc.)

Fertilizers and Tillage PLS /23/05 p. 5 Tillage systems Two types, depending on degree of soil stirring: Conventional versus Conservation Tillage Conventional tillage used primary and secondary tillage operations. Primary tillage- topsoil is stirred to a depth of 6-14” a slice of soil is cut and inverted, burying the plant debris from the surface. This produces a rough surface, and takes lots of fuel.

Fertilizers and Tillage PLS /23/05 p. 6 Tillage systems Secondary tillage- follows primary tillage to produce a finer tilth for seeding. Plowing is a primary tillage operation, while disking, harrowing, and listing are secondary tillage practices Soil moisture and texture are very important in the determination of tillage timing and equipment that is used.

Fertilizers and Tillage PLS /23/05 p. 7 Advantages of conventional tillage 1. Even though tillage causes compaction, it is the best way to manage soil compaction when it occurs. 2. Clean soil is easier to apply fertilizers and seed. 3. Lack of crop residue reduces pest populations. (less overwintering or oversummering)

Fertilizers and Tillage PLS /23/05 p. 8 Diasdvantages of conventional tillage 1. Erosion 2. Compaction 3. Cost (fuel, machines, time) 4. Loss of soil organic matter

Fertilizers and Tillage PLS /23/05 p. 9 Conservation tillage crop residue management systems No-tillage, zero tillage, direct drilling, direct seeding Mulch tillage Strip tillage Minimum tillage Ridge tillage

Fertilizers and Tillage PLS /23/05 p. 10 Advantages of conservation tillage 1. Reduced erosion from wind and water. 2. Reduced compaction. 3. Applicable to steep slopes. 4. Better infiltration and water conservation. 5. Reduced costs of production. 6. Soil temperature modification. 7. Increased soil organic matter content.

Fertilizers and Tillage PLS /23/05 p. 11 Disadvantages of conservation tillage 1. Dependence on chemicals (mainly herbicides) 2. Costs (new equipment) 3. Higher risks of pests during establishment. 4. Higher soil moisture increases risks of nitrate leaching. 5. Crop residue impedes fertilizer applications. 6. High herbicide use increases risk of weeds becoming resistant to the herbicide. 7. New weed species become a problem.

Fertilizers and Tillage PLS /23/05 p. 12 Tillage implements Primary tillage Moldboard plow Disk plow Chisel plow Powered rotary tiller Sweep plow = stubble mulch plow Lister/bedder

Fertilizers and Tillage PLS /23/05 p. 13 Tillage implements, con’t. Secondary tillage Disk harrow Harrow Field cultivator

Fertilizers and Tillage PLS /23/05 p. 14 Tillage implements, con’t. Special tillage operations Deep tillage- can be used to bury topsoil with a problem (like salinity). Subsoiling- is used to break up compaction and plow pans or hard pans in soil.

Fertilizers and Tillage PLS /23/05 p. 15 Tillage practices use considerable energy Fuel, equipment, etc. Shift from gasoline to diesel tractors (more efficient) saw a 25% reduction in energy use by the agricultural sector in the USA.

Fertilizers and Tillage PLS /23/05 p Gasoline 42%11% (% of on farm energy use) Diesel use 13%29% Agricultural output increased by 47% during this period.