Since the mid‐1940s, varieties and cultural practices have changed for cotton (Gossypium hirsutum L.) grown in the southeastern USA. We believed a more current investigation of dry matter production rates and nutrient uptake patterns was needed for representative cotton cultivars. Field studies were conducted to determine if dry matter production and distribution, and nutrient uptake and distribution are affected by the cultivar of cotton grown under nonirrigated conditions. Four cotton cultivars were compared: Deltapine 90, Stoneville 825, Coker 315, and Paymaster 145. The experiment was conducted on a nonirrigated Decatur silt loam (clayey, thermic, kaolinitic Rhodic Paleudults) and a Norfolk silt loam (fine loamy, thermic siliceous Typic Paleudults). Soil fertility was uniform within a given site. Intact cotton plants were harvested at 14‐d intervals throughout the growing season starting at 15 d after emergence, and separated into leaves, stems, burs, seed, and lint. Total dry matter production averaged 7923 kg ha−1 in 1986 and 7695 kg ha−1 in 1987 on the Decatur soil, and 6726 kg ha−1 on the Norfolk soil in 1986. The four cultivars produced and partitioned dry matter similarly within a location. Differences between locations (soils) were not related to a difference in cumulative heat units. Total N, P and K uptake averaged 128, 17.3 and 106 kg ha−1, respectively. Cotton plants from the study removed an average of 19.9 kg N, 2.5 kg P and 15.3 kg K for every 100 kg lint. Nutrient concentrations and nutrient uptake by a plant part, and total nutrient uptake were not affected by the cotton variety.

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Four soils, ranging in texture from loamy sand to clay, were fertilized differently and equilibrated moist for several days. Soil solutions were then separated by column‐displacement, by simple centrifugation, and by immiscible displacement with CCl4 via centrifugation. The ionic compositions of soil solutions were unaffected by the method used to obtain the solutions.

Cotton (Gossypium hirsutum L.) production is intensive in many areas of the southeastern USA, and the common tillage system used is a highly erosive fall plow‐winter fallow‐spring disk. The primary purpose of this 3‐yr field study was to evaluate seeding systems for winter cover crops, effect of cover crop management on cotton production, and N fertilizer requirements for cotton following various winter cover crops. Treatments consisted of (i) winter cropping systems [fall plow‐winter fallow; winter fallow; and three cover crops, rye (Secale cereale L.), hairy vetch (Vicia villosa Roth.), and crimson clover (Trifolium incarnatum L.)]; (ii) cover crop seeding methods (broadcast interseeded prior to cotton defoliation or drill seeded after picking); (iii) spring tillage (disk or no tillage prior to cotton planting); and (iv) N rates for cotton (0, 34, 67, and 101 kg N ha−1). The soil was a Decatur silt loam (clayey, kaolinitic, thermic, Typic Paleudults). Interseeding resulted in adequate cover crop stands for all covers each year, but drill seeded clover winter killed 2 out of 3 yr. Total N in the legume tissue at cotton planting was higher for interseeded (120–145 kg N ha−1) than drill seeded (33–86 kg N ha−1). In 1 of the 3 yr, cotton seedling mortality was higher with no tillage than disk tillage. None of the conservation‐tillage systems resulted in higher cotton yields than the fall plow system. Planting into killed rye resulted in yields equal to the fall plow system, but more fertilizer N (approximately 34 kg N ha−1) was required for cotton planted into rye. When cotton followed vetch, yields were equal to the fall plow system in 2 of the 3 yr, and N fertilizer requirements were reduced approximately 34 kg ha−1. When compared with fall plow, no tillage into clover or winter fallowed soils resulted in inferior cotton yields each year.