| Abstrakt: |
Field research in northeastern Arkansas continued to evaluate N fertilizer management for cotton (Gossypium hirsutum) in rotation with peanut (Arachis hypogaea). The on-farm study was conducted in a 40-ac commercial Mississippi County field with sandy, alluvial soils [Routon-Dundee-Crevasse complex (Typic Endoqualfs)]. It was the 2nd year of cotton in rotation following peanut. Fertilizer applications and yield assessments were made with the cooperating producer's equipment. A base rate of 80 lb N/ac was broadcast applied to all plots in the week of first squares, 34 days after planting (DAP), followed by topdress applications of 0, 25, 40, or 55 lb N/ac made at first flowers (58 DAP), which resulted in total-N rates of 80, 105, 120, and 135 lb N/ac. The Arkansas Extension recommendation for the production region is 110 lb N/ac. In-season plant monitoring with COTMAN was used to quantify maturity delay and to identify plant structural changes in response to N in different soil textural zones of the spatially variable field. Soil electrical conductivity measures (ECa) were used as a proxy for soil texture to classify zones. Our results showed that there were significant treatment effects on lint yield and fiber quality. There were differences in yield among soil texture classes and fertilizer-N rates. In 2021, a yield response to increased N was noted only in the coarse-sand textured soil (ca. 35% of the field); however, in the 2022 study, overall yield increased in both soil textural zones. A maturity delay of ca. two weeks was observed with plants in loamy sand areas receiving the highest N rates. With good fall growing conditions, bolls set in late season contributed to yield. Additional research is needed to increase the understanding of the cotton-peanut rotation benefits and how directed soil sampling for N fertilization could improve N fertilizer management efficiency for mid-South cotton producers. [ABSTRACT FROM AUTHOR] |
