SCIENCE@home

Soil pH, Soil Organic Matter, and Crop Yields in Winter Wheat–Summer Fallow Systems

R. Ghimire,S. Machado,Prakriti Bista

Published 2017 in Agronomy Journal

ABSTRACT

Agronomy Journa l • Volume 109, I s sue 2 • 2017 Soil acidification has become a major environmental challenge for crop production in the U.S. iPNW (Rasmussen and Rohde, 1989; Brown et al., 2008). Th e iPNW represents the largest area under dryland farming with more than 2 million ha under WW–SF system (Schillinger et al., 2003; Schillinger and Papendick, 2008). Introduction of chemical N fertilizers, mechanized equipment, and crop breeding and management practices in the iPNW in 1940s improved effi ciency of dryland farming in the region (Schillinger and Papendick, 2008). However, continuous use of chemical fertilizer and intensive tillage deteriorated soil quality and negatively aff ected agricultural sustainability through soil acidifi cation and SOC and nutrient loss (Mahler et al., 1985; Rasmussen and Rohde, 1989; Schillinger and Papendick, 2008). In general, soils are strongly buff ered by ion exchange reactions and it takes 100 to 1000 yr for soil pH to change under natural conditions (Chadwick and Chorover, 2001). Soils in some parts of eastern Oregon and Washington, however, were acidifi ed within 30 to 40 yr of N fertilizer applications (Mahler et al., 1985), and most farmers are not taking any measures to remedy the situation. In fact, N fertilizer use in wheat production, mostly ammoniacal, has increased from an average of 69 kg N ha–1 in 1993 to 90 kg N ha–1 in 2012 (USDA-ERS, 2013). Th e demand for N use in North America is expected to increase by about 0.5% between 2014 and 2018, according to Food and Agricultural Organization data (FAO, 2015). To this end, soil pH will continue to decrease below optimum levels for wheat production unless changes to fertility management to slow down acidifi cation are implemented. Meanwhile, area under reduced-tillage (e.g., subsurface sweep, disk), no-tillage, and fertility management practices is increasing to improve soil and water conservation and sustainable crop production in drylands (Schillinger and Papendick, 2008). It is not clear how these alternative tillage and fertility management practices infl uence soil acidity, soil quality, and crop production in dryland WW–SF systems. Available information indicated that reduced-tillage and no-tillage cropping systems concentrate fertilizer in the seed zone thereby increasing acidity in the top surface soil layers. Soil pH, Soil Organic Matter, and Crop Yields in Winter Wheat–Summer Fallow Systems

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-37 of 37 references · Page 1 of 1

CITED BY

Showing 1-68 of 68 citing papers · Page 1 of 1