Impact of Organic Production Practices on Soil Quality Indicators

• Published in: Journal of environmental quality Vol. 28; no. 5; pp. 1601 - 1609
• Main Authors: Liebig, M. A., Doran, J. W.
• Format: Journal Article
• Language: English
• Published: Madison, WI American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America 01.09.1999; Crop Science Society of America; American Society of Agronomy
• Subjects: Agricultural and farming systems; Agronomy. Soil science and plant productions; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; Soil quality; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; United States; North America; North Dakota; America; Nebraska; Production system; Biological properties; Laboratory study; System evaluation; Cultural practice; Soil tillage; Soil fertility; Cultivated soil; Cropping system; Property of soil; Soil quality; Organic fertilization; Impact study; Nitrates; Physical properties; Soil management; Indicator; Regional study; Organic agriculture; Environment impact; Chemical properties; Comparative study; Field study
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq1999.00472425002800050026x

The impact of organic production practices on soil quality indicators, for selected farms in Nebraska and North Dakota, were evaluated to better understand their effects on soil quality and sustainability. Conventional production practices were the standard to which the effects of organic production were compared. Five organic and conventional farms, matched by soil type, were chosen for the study. Soil properties recognized as basic soil quality indicators were measured on each farm at depths of 0 to 7.6 and 0 to 30.5 cm. Averaged across locations, there was 22% more organic C (12 571 kg ha−1) and 20% more total N (970 kg ha−1) on organic farms than conventional farms in the surface 30.5 cm. At four of five locations, organic farms had soil pH closer to neutral, lower bulk density, and higher available‐water holding capacity, microbial biomass C and N, and soil respiration as compared with conventional farms. Nutrient levels above crop needs were observed in both organic and conventional farms indicating the potential for negative environmental impacts. Despite this, organic farms often had more potentially mineralizable N (anaerobic incubation) relative to NO3‐N in the surface 30.5 cm. For conditions of this study, the capacity of organic production practices to improve soil quality was mainly due to use of more diverse crop sequences, application of organic amendments, and less frequent tillage.