Unit 7: Tillage & Seeding CROP PRODUCTION Unit 7: Tillage & Seeding

Tillage & Seeding (149) Tillage – manual or mechanical soil stirring actions Tillage Systems – type and sequence of tillage operations used for proper establishment and growth of crops

Goals & Purposes (149) Seedbed Preparation – provide optimum environment for seed germination and subsequent growth Temperature Moisture Aeration Seed-to-soil contact Incorporating and mixing – crop residues, lime, fertilizers, and/or pesticides Weed control Conservation of soil & water – prevent erosion conserve precipitation, and improve infiltration

Tillage Vocabulary (150) Primary Tillage – inverts or shatters soil 6-14 inches deep; leaves the soil rough Loosen and aerate surface layer Incorporate fertilizer Cover plant residue Secondary Tillage – follow primary tillage; depth is 2-6 inches deep Prepare final seed bed Level and firm soil Pulverizing soil for seed-to-soil contact Control weeds

Tillage Vocabulary (150) Tillage Implements – vary widely among engineers, agronomists, manufacturers, and producers Compaction – soil has few or no pore spaces, creating a poor environment for plant roots; measured with a penetrometer (on right)

Primary Tillage Implements V-ripper disk plow disk ripper sweep plow lister/bedder moldboard plow powered rotary tiller chisel plow—combo

Secondary Tillage Implements disk harrow roller packer field cultivator spring- spike- & tine-tooth harrows seed bed finisher row-crop cultivator

Tillage Systems (156) Conventional tillage: normal primary and secondary operations – varies from region to region Clean tillage: leave little or no residue on soil surface Mulch tillage: leave residue to reduce soil/water loss Conservation tillage: leave >30% residue cover on soil surface Minimum tillage: systems that employ the least amount of tillage required

Tillage Systems (Con’t) (156) Reduced tillage: utilize fewer or less energy intensive operations Full-width tillage: tillage of entire field surface Strip tillage: tillage of strips, leaving undisturbed strips No-till: seed planted directly into previously undisturbed soil Ridge tillage: ridges/furrows established & maintained throughout the year

Tillage Methods (156) Clean, full-width tillage systems Conventional tillage Plow and combined secondary tillage Plow and strip-till planting Plow, listing, and planting Other clean, full width tillage systems

Tillage Methods (159) Conservation tillage systems Full width conservation tillage Chisel plow systems Disk (and/or field cultivating) and plant Sweep tillage Strip till conservation tillage Lister-planting Strip rotary tillage Till-plant No till

Tillage Operations for Special Situations (164) Sub-soiling: used to break up impervious layers which limit root growth and nutrient and water holding capacities of the soil Depths greater than 13-14 inches Extremely deep primary tillage: as deep as four feet; turn up soil that has been buried

Tillage for Weed Control (165) Tillage before planting – as weeds germinate and begin growth Tillage after planting and before crop emergence is completed – both weed control and breaking soil crusts Cultivation after crop emergence – most economical and surest method for weed control

General Considerations (166) Agronomic aspects in adopting tillage systems: Soil and climatic factors – more crop residues = lower soil temps and higher OM levels Seed and fertilizer placement – heavy residues interfere with seed placement, covering seed with soil and seed-to-soil contact; fertilizer may be highly unavailable Pest control – reduced tillage systems allow weeds seeds to remain near surface Soil conservation – erosion directly linked to surface residue Economic aspects in adopting tillage systems – primary consideration is net profit over long period of time

Objectives of Seeding (169) Proper depth placement – large seeds have large food reserves and longer hypocotyl/mesocotyl; in some soils, moisture is unavailable at shallow depths Good seed-to-soil contact – proper planting procedure and equipment; proper tillage; avoid “crusting” Proper rate and distribution – germination and purity; competitive ability; other environmental factors: canopy, tillering, competition w/other species

Objectives of Seeding (172) Time of planting – late planting can lead to lower yield Row fertilizer placement – side-band, split boot, and pop-up

Manual Planting (173) Problems: Uneven depth Uneven spacing Uneven covering of seed Excessive soil compaction

Mechanized Planting (173) Row-crop planters – drill patterns, hill-drop pattern, check row pattern Grain drills Broadcast seeders – disadvantages such as uneven distribution/spacing, poor soil contact, requires higher seeding rates Specialized planters – potato planters, vegetable seed planters, and tobacco planters

Website resouces: Chapter 7 http://www.wtamu.edu/%7Ecrobinson/TILLAGE/tillage.htm http://www.deere.com http://www.wil-rich.com/ Chapter 7 Review Questions (p. 182-184) Thinker