Browse on keywords: grass organic matter
Search results on 05/24/13
2918. Idaho Agr. Expt. Sta.. 1950. Annual Report. Id Agr. Expt. Sta. Bull. #280.
T: hay yields, economics
4358. McHenry, J.R., L.T. Alexander and L.L. Zook. 1946. Carbon and nitrogen contents of a chernozem soil as affected by age of perennial grass sods.. Soil Sci. Soc. Am. Proc. 11:407-412.
Compared soil organic carbon and nitrogen changes due to perennial grass established 0-9 yrs; C and N decreased under all treatments, although the changes were slight with more than 6 yr sod; only with >6 yr sod were C and N % significantly greater than continuous cultivation; the system may have been nutrient limited, or it may take longer to develop equilibrium; root mass ranged from 1600-5200 lb/ac/yr. T: carbon and nitrogen levels; root mass.
6720. Stephenson, R.E.. 1941. Humus for Oregon soils.. OR Agr. Expt. Sta. Circ. #143.
Four tons of stable manure were equal in value to 5 tons of green manure plowdown. The humus renewal of 1 yr legume sod equaled the humus lost during 1 yr row cropping. Plant material should never be burned. Fresh additions of organic matter stimulate root developement. Alfalfa for soil building - 2/3 of roots left below plow layer. Pea green manure raised OM content by 0.2% after 4 crops. Prairie grass adds 4T/ac roots in 4" of soil. T: organic matter levels and changes.
8588. U.S.D.A.. 1948. Grass: The Yearbook of Agriculture.. U.S. Govt. Printing Office, Washington, D.C..
This volume is dedicated to a "permanent agriculture" and focuses on the use of perennial grasses and legumes in cropping systems. In discussing the effects of grass on soil, it is stated that organic matter accumulation occurs somewhat slowly during the first few years until a good relationship is reached among the microscopic plants and animals, the higher plants, and the higher animals that live in the soil. Following the establishment of this favorable relationship, the rate of accumulation increases rapidly for many years and then slows again. In medium textured soils of well-balanced mineral composition, it is thought that the maximum content of organic matter will be attained in several hundred years. The book contains many tables listing common and species names, management needs, and characteristics of hundreds of grasses and legumes.
9809. Weaver, J.E. and G.W. Harmon. 1935. Living materials in prairie soils in relation to run-off and soil erosion.. Univ. Nebraska Bull. 8:1-53, Conservation Dept..
describes root mass contributions by various grass and cultivated crops.