Nitrogen mineralization in a pecan (Carya illinoensis K. Koch)-cotton (Gossypium hirsutum L.) alley cropping system in the southern United States

• Published in: Biology and fertility of soils Vol. 41; no. 1; pp. 28 - 37
• Main Authors: Allen, S.C, Jose, S, Nair, P.K.R, Brecke, B.J, Nair, V.D, Graetz, D.A, Ramsey, C.L
• Format: Journal Article
• Language: English
• Published: Berlin Springer 2005; Springer Nature B.V
• Subjects: Agricultural wastes; Agrochemicals; Agronomy. Soil science and plant productions; Alley cropping; Biological and medical sciences; Carya illinoinensis; Cotton; Crop yield; Cropping systems; Environmental factors; fallow; fertilizer application; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Gossypium hirsutum; Growing season; immobilization in soil; lint cotton; Litter; Mineral fertilizers; Mineralization; Nitrogen; Nutrient uptake; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; pecans; Physical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Poultry; poultry manure; Soil science; soil temperature; soil water content; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; temporal variation; Water and solute dynamics; Florida; Poultry litter, soil water; SOIL BIOLOGY; Organic and inorganic nitrogen sources; Litter; Poultry manure; Soil moisture; Alley cropping; Property of soil; Organic fertilization; Organic fertilizer; Physical properties; Nitrogen mineralization; Soil water properties; Inorganic nitrogen; Mineralization; Soil science; Temperate alley cropping; Soil temperature
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/s00374-004-0799-2

Information on temporal and spatial patterns of N mineralization is critical in designing tree-crop mixed systems that could maximize N uptake while minimizing N loss. We quantified N mineralization rates in a pecan (Carya illinoensis K. Koch)-cotton (Gossypium hirsutum L.) alley cropping system in northwestern Florida with (non-barrier) and without tree-crop belowground interactions (barrier separating the root systems of pecan and cotton). Monthly rates of mineralization were estimated using buried bag incubations over a 15-month period. In addition, seasonal mineralization rates and cotton lint yield on soils supplied with two sources of N--inorganic fertilizer and organic poultry litter--were assessed. Results indicated that temporal variations in net NH^sub 4^ and NO^sub 3^ accumulation and mineralization rates were driven primarily by environmental factors and to a lesser degree by initial soil NH^sub 4^ and NO^sub 3^ levels. Mineralization varied by belowground interaction treatment during the initial growing season, when the non-barrier treatment exhibited a higher mineralization rate than the barrier treatment, likely due to reduced nutrient uptake by cotton in the non-barrier or a higher degree of immobilization in the barrier treatment. Mineralization during the second growing season was similar for both treatments. Source of N had no effects on N transformation in the soil. Lint yield reductions were observed in the non-barrier treatment during both years compared to the barrier treatment, likely due to interspecific competition for water. Yield differences between treatments in the second growing season were likely compounded by a diminishing pre-study fallow effect. Source of N was found to have a significant effect on cotton yield, with inorganic fertilizer resulting in 39% higher lint compared to poultry litter in the barrier treatment.[PUBLICATION ABSTRACT]