Browse on keywords: tillage crop residue
Search results on 05/24/13
1827. Elliott, L.F. and R.I.Papendick. 1986. Crop residue management for improved soil productivity.. Biological Agriculture and Horticulture 3:131-142.
Residue management is critical to maintaining soil structure and organic matter. Surface management of residue along with reduced tillage seems the best approach. A seeding drill has been developed to plant in heavy residue and to move residue away from the seed. Mating this approach with organic farming appears viable, with no or very little use of synthetic fertilizer. Row crop weed control is also viable with this system. This paper contains an excellent discussion on micro aggregate formation/stability and the importance of microbiol activity. There is also a discussion on biological activity in conventional and organically farmed soil.
6583. USDA Soil Conservation Service. 1974. Soil conditioning rating indices for major irrigated and non-irrigated crops grown in the Western U.S.. Conservation Agronomy Technical Note No. 27.
This document presents a rating system to judge how various cropping systems affect soil condition over time. It assigns numerical values to various practices and totals them over a rotational sequence, with either a +, -, or neutral outcome. It is not a method for determining erosion. The concepts presented are helpful in assessing "soil quality" for cropping systems, both irrigated and dryland.
10225. Rasmussen, P.E. and H.P. Collins. 1991. Long-term impacts of tillage, fertilizer, and crop residue on soil organic matter in temperate semi-arid regions.. Advances Agronomy 45:93-134.
Organic matter is an important soil component in semi-arid regions. Virgin grassland soils lose organic matter rapidly upon first cultivation, with the greatest decline in the first 10-20 years. A new equilibrium is usually established after 50-60 years. Long-term experiments or paired comparisons are needed to evaluate change in organic matter due to managment. Organic matter loss is greater with increasing frequency of fallow and intensity of tillage. Conservation tillage generally increases organic matter, and results from studies worldwide are presented. N fertilizer generally leads to higher organic matter, since it boosts biomass production. About 18% of the applied N at Pendleton was incorporated into the organic fraction in a wheat-fallow system. Amount of crop residue influences organic matter levels far more than type of residue. Organic matter increases linearly with increasing residue additions. Semi-arid soils can sequester from 10-25% of the C added. Many agricultural soils are not receiving sufficient C additions to prevent continued organic matter loss under current management.