Journal Article

Carbon Supply and Storage in Tilled and Nontilled Soils as Influenced by Cover Crops and Nitrogen Fertilization

Singh, B.P, Whitehead, W.F, Wang, S, Sainju, U.M

2006

Overview

Soil carbon (C) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant C inputs and their rate of mineralization. We examined the influence of four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)} and three nitrogen (N) fertilization rates (0, 60 to 65, and 120 to 130 kg N ha-1) on C inputs from cover crops, cotton (Gossypium hirsutum L.), and sorghum [Sorghum bicolor (L.) Moench)], and soil organic carbon (SOC) at the 0- to 120-cm depth in tilled and nontilled areas. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic Plinthic Paleudults) from 1999 to 2002 in central Georgia. Total C inputs to the soil from cover crops, cotton, and sorghum from 2000 to 2002 ranged from 6.8 to 22.8 Mg ha-1. The SOC at 0 to 10 cm fluctuated with C input from October 1999 to November 2002 and was greater from cover crops than from weeds in no-tilled plots. In contrast, SOC values at 10 to 30 cm in no-tilled and at 0 to 60 cm in chisel-tilled plots were greater for biculture than for weeds. As a result, C at 0 to 30 cm was sequestered at rates of 267, 33, -133, and -967 kg C ha-1 yr-1 for biculture, rye, vetch, and weeds, respectively, in the no-tilled plot. In strip-tilled and chisel-tilled plots, SOC at 0 to 30 cm decreased at rates of 233 to 1233 kg C ha-1 yr-1. The SOC at 0 to 30 cm increased more in cover crops with 120 to 130 kg N ha-1 yr-1 than in weeds with 0 kg N ha-1 yr-1, regardless of tillage. In the subtropical humid region of the southeastern United States, cover crops and N fertilization can increase the amount of C input and storage in tilled and nontilled soils, and hairy vetch and rye biculture was more effective in sequestering C than monocultures or no cover crop.

• Publisher: American Society of Agronomy, Crop Science Society of America, Soil Science Society,Crop Science Society of America,American Society of Agronomy
• Subject: Agricultural practices / Agriculture / Agriculture - methods / Agronomy. Soil science and plant productions / analysis / application rate / Applied sciences / Biological and medical sciences / Biotechnology / Carbon / Carbon - metabolism / carbon dioxide / carbon sequestration / chemistry / Cotton / Cover crops / Crop management / Crop residues / Crops, Agricultural / Crops, Agricultural - growth & development / Earth sciences / Earth, ocean, space / Engineering and environment geology. Geothermics / Environment and pollution / Environmental Monitoring / Exact sciences and technology / fertilizer application / Fertilizers / Fundamental and applied biological sciences. Psychology / Georgia / global warming / Gossypium hirsutum / Grain / Greenhouse gases / growth & development / Industrial applications and implications. Economical aspects / legumes / metabolism / methods / Mineralization / Monoculture / Nitrogen / Nitrogen - metabolism / Organic carbon / Organic Chemicals / Organic Chemicals - chemistry / Organic Chemicals - metabolism / Pollution / pollution control / Pollution, environment geology / Sandy loam / sandy loam soils / Secale cereale / Soil / Soil - analysis / Soil erosion / soil organic carbon / soil-plant-atmosphere interactions / Soils / Sorghum / Sorghum bicolor / Terrestrial ecosystems / Tillage / Time Factors / Vicia villosa / Weeds