Browse on keywords: fertility conservation tillage
Search results on 06/18/13
9658. Klepper, B., P.E. Rasmussen and R.W. Rickman. 1983. Fertilizer placement for cereal root access.. Journal of Soil and Water Conservation (May/June) p. 250-252..
Conservation tillage, which involves surface crop residue often results in seedbed and near-surface soil environments that are not always as suitable as they might be for growth of cereal grain seedlings. Microbial decomposition of surface residue or partially incorporated residue immobilizes mineral nutrients, particularly nitrogen. Placing fertilizer deep in the soil usually offsets the immobilization effects some, but proper location is important for maximum root access by young plants. Small amounts of starter fertilizer can be banded with the seed. Applying the entire crop requirement, however, may delay or stop seed development. Fertilizer injury to roots - Placement of fertilizer too close to a seed can delay emergence and injure seedling. The injury is usually to the tips of the first three seminal roots. Optimum fertilizer placement - Farmers should place nutrients below residue accumulation zones for most efficient crop use. A distance of 3 to 5 cm below and up to 5 cm to one side is sufficient in a silt loam soil.
9764. Varvel, G.E., J.L. Havlin and T.A. Peterson. 1989. Nitrogen placement for winter wheat in three fallow tillage systems.. Soil Sci. Soc. Am. J. 53:288-292.
Increased soil water storage with increasing amounts of surface residue in winter wheat-fallow cropping systems has not consistently resulted in higher grain yields in the Great Plains. Earlier results had suggested increased amount of surface residue may increase N immobilization and limit N availability, thereby reducing potential for use of the additional stored soil water. This study was conducted to determine if N placement below the zone of organic matter or surface residue accumulation would reduce N immobilization and increase yields.