Browse on keywords: erosion organic matter WA
Search results on 01/21/18
2735. Horner, G.M., M.M. Oveson, G.O. Baker, and W.W. Pawson.. 1960. Effect of cropping practices on yield, soil organic matter and erosion in the Pacific Northwest wheat region.. PNW Technical bulletin 1; USDA-ARS and Ag. Expt. Sta.'s of ID, OR, WA.
Summary of soil management experiments conducted over 40 yrs at six experiment stations. Covers: crop rotation, fertilization, and use of organic material. Some results: sweetclover and alfalfa were more effective than other legumes in increasing wheat yield. Yields of wheat were markedly affected by the sequences of cropping. Return of straw to soil decreased yields slightly under low N conditions. Organic and mineral N had no effect on yields in low precip. zones. Also covers runoff and erosion. T: many, eg.: effect of crop rotations on crop yield; crop yield as affected by grass/clover; effect of OM on wheat yield.
3210. Bhatti, A.U.. 1990. Spatial variability and geostatistical estimation of soil properties and wheat yield on eroded lands in the Palouse region.. Chpt. 3, PhD. Dissertation, Dept. of Agronomy & Soils, Washington State Univ., Pullman, WA 99164.
Spatial variability of organic matter, soil P, and wheat yields was studied using classical statistical and geostatistical approaches on two commercial wheat farms in the Palouse region of eastern Washington. Geostatistics indicated strong spatial relationship of soil properties and wheat yields with a range of influence of 50-200 m. The two sites differed greatly in spatial patterns due primarily to differences in topography and the extent of erosion and topsoil loss. As a consequence of topsoil loss and reductions in organic matter, it was demonstrated that spatial patterns in yield and soil phosphorus were strongly correlated with organic matter patterns. Remote sensing of soil organic matter and the use of geostatistics offers a way to quickly assess spatial patterns in grain yield and available phosphorus.
3348. Jaffri, M.Z.. 1956. Effect of farming systems on soil losses, organic matter changes, and trends in productivity of land in the Palouse wheat-pea area.. M.S. Thesis, Washington State College, Pullman, WA.
An excellent study to determine the effect of cropping systems, tillage practices, fertilizers, and conservation practices on soil loss and soil organic matter changes, and to future soil productivity. T: many.
5771. Reganold, J.P., L.F. Elliott and Y.L. Unger. 1987. Long-term effects of organic and conventional farming on soil erosion.. Nature, 330(26 Nov.):370-372.
The long-term effects (since 1948) of organic and conventional farming on selected properties of the same soil are compared. The organically-farmed soil had significantly higher organic matter content, thicker topsoil depth, higher polysaccharide content, lower modulus of rupture and less soil erosion than the conventionally-farmed soil. This study indicates that, in the long term, the organic farming system was more effective than the conventional farming system in reducing soil erosion and, therefore, in maintaining soil productivity. T: Mean values of conventional and organic farm soil properties.
5761. Reganold, J.P.. 1988. Comparison of soil properties as influenced by organic and conventional farming systems.. Am. J. Alt. Agric., 3(4):144-155.
This paper summarizes data from previous and current studies on two adjacent farms, one organically managed and the other conventionally managed, in the Palouse region of eastern Washington. The 320-hectare organic farm has been managed without the use of commercial fertilizers and only limited use of pesticides since the farm was first plowed in 1909. The 525-hectare conventional farm, first cultivated in 1908, began receiving recommended rates of commercial fertilizers and pesticides in 1948 and the early 1950's, respectively. The organically-farmed Naff silt loam soil had significantly higher organic matter, cation exchange capacity, total nitrogen, extractable potassium, water content, pH, polysaccharide content, enzyme levels, and microbial biomass than did the conventionally-farmed Naff soil. Also, the organically-farmed soil had significantly lower modulus of rupture, more granular structure, less hard and more friable consistence, and 16 centimeters more topsoil. This topsoil difference between farms was attributed to significantly greater erosion on the conventionally-farmed soil between 1948 and 1985. The difference in erosion rates between farms was most probably due to their different crop rotation systems; i.e., only the organic farm included a green manure crop in its rotation, and it had different tillage practices. These studies indicate that, in the long-term, the organic farming system was more effective than the conventional farming system in maintaining the tilth and productivity of the Naff soil and in reducing its loss to erosion.
10377. Pierson, F.B. and D.J. Mulla. 1990. Aggregate stability in the Palouse region of Washington: effect of landscape position.. Soil Sci. Soc. Amer. J. 54:1407-1412.
Spatial patterns of aggregate stability were studied in the steeply rolling Palouse hills. Aggregate stability and organic C content were highest in footslope and toeslope positions, and lowest at the summit. Clay content was just the opposite. Aggregate stability patterns were closely related to changes in a few key properties, namely, organic C content and landscape position. Soil erosion had removed topsoil and organic matter from the ridgetops, thus exposing subsoil horizons which are higher in clay content and lower in aggregate stability.