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United States Department of Agriculture

Agricultural Research Service

Title: Soil and crop nitrogen as influenced by tillage, cover crops, and nitrogen fertilization

Authors
item Sainju, Upendra
item Wang, Shirley - FORT VALLEY STATE UNIV
item Singh, Bharat - FORT VALLEY STATE UNIV
item Whitehead, Wayne - FORT VALLEY STATE UNIV

Submitted to: World Congress of Soil Science
Publication Type: Abstract Only
Publication Acceptance Date: March 24, 2006
Publication Date: July 9, 2006
Citation: Sainju, U.M., Wang, S., Singh, B.P., Whitehead, W. 2006. Soil and crop nitrogen as influenced by tillage, cover crops, and nitrogen fertilization. World Congress of Soil Science, July 9-15, 2006, Philadelphia, PA. Paper No. 155-148. Page 141.

Technical Abstract: Soil and crop management practices may influence soil mineral N, crop N uptake, and N leaching. We evaluated the effects of three tillage practices [no-till (NT), strip till (ST), and chisel till (CT)], four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], vetch + rye biculture, and winter weeds or no cover crop}, and three N fertilization rates (0, 60 to 65, and 120 to 130 kg N ha-1) on soil NH4-N and NO3-N contents at the 0 to 120 cm depth and N uptake by cotton (Gossypium hirsutum L.) and sorghum [Sorghum bicolor (L.) Moench] from 2000 to 2002 in central GA. Nitrogen in cotton, sorghum, and cover crop residues (stems + leaves) was returned to Dothan sandy loam (fine-loamy siliceous thermic Plinthic Paleudults). Nitrogen supplied by cover crops was higher in vetch and vetch + rye than in rye and weeds. Soil NH4-N content at 0 to 30 cm was higher at harvest than at planting of cotton and sorghum and higher in NT or vetch with 120 to 130 kg N ha-1 than with other treatments. The NO3-N content at 0 to 120 cm varied with date of sampling and was higher with vetch than with rye and weeds. The NO3-N content at 0 to 10 cm was higher in CT with vetch than in NT and ST with rye or weeds. From November 2000 to April 2001 and from November 2001 to April 2002, N loss from crop residue and soil at 0 to 120 cm was higher with vetch than with other cover crops, probably due to leaching. Nitrogen removed by cotton lint and seed was higher with rye than with other cover crops in 2000 and higher with 0 and 60 than with 120 kg N ha-1 in 2002 but N removed by sorghum grain and cotton and sorghum biomass were higher with vetch than with rye and higher with 120 to 130 than with 0 kg N ha-1. Because of higher N supply, vetch increased soil mineral N and cotton and sorghum N uptake compared with rye but also increased the potential for N leaching, regardless of tillage and N fertilization. The potential for N leaching can be reduced and crop N uptake can be optimized by mixing vetch with rye.

Last Modified: 11/23/2014
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