Core Ideas Soil organic C was two times greater with a no‐tillage rye cover crop system compared with conventional tillage (winter fallow) 17 yr after imposing treatments. A greater rate of C gain was observed with a no‐tillage mixed species cover crop system than with a rye cover crop in a 3‐yr period. Cotton lint yield and gross margins were less with a no‐tillage rye cover crop system than conventional tillage. Differences of lint yield and gross margins did not exist between the conventional tillage and no‐tillage mixed species cover crop treatments. Conservation tillage coupled with winter cover crops may reduce wind erosion in the North America Great Plains. Although farmers recognize the benefits of conservation practices, their decision to use cover crops is often based on the farm’s operating budget. In semiarid ecoregions dependent on irrigation for cotton (Gossypium hirsutum L.) production and limited groundwater resources, cover crops using stored soil moisture is a major concern. The objective of this research was to quantify the long‐term impacts of conservation tillage and cover crop use on C storage, cotton lint yield, and economic returns in monoculture cotton production. Conservation tillage and rye cover were implemented in 1998 and a mixed species cover of rye (Secale cereale L.), hairy vetch (Vicia villosa Roth), radish (Raphanus sativus L.), and winter pea (Pisum sativum L.) was seeded in 2014 into half of the rye cover crop plots. Soil organic C in the top 15‐cm soil depth was increased by combining conservation tillage with winter cover crops. Cotton lint yield was less with no‐tillage and the rye cover when compared with conventional tillage in 2 of 3 yr. As a result, cotton lint revenue and gross margins of conservation tillage were on average less than conventional tillage.

Irrigated agriculture is a major economic contributor of the High Plains Region and it primarily relies on the High Plains Aquifer as a source of water. Over time, areas of the High Plains Aquifer have experienced drawdowns limiting its ability to supply sufficient water to sustain fully irrigated crop production. This among other reasons, including variable climatic factors and differences in state water policy, has resulted in some areas adopting and practicing deficit irrigation management. Considerable research has been conducted across the High Plains Aquifer region to identify locally appropriate deficit irrigation strategies. This review summarizes and discusses research conducted in Nebraska, Colorado, Kansas, and Texas, as well as highlights areas for future research. Editor's note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.

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Boll distribution provides an important assessment of the response and adaptation of upland cotton (Gossypium hirsutum L.) to its environment and is strongly linked to yield and fiber quality and consequently to economic value. Several studies have measured boll distribution through end-of-season field or box mapping to study the spatiotemporal characteristics of bolls at both the plant and field levels, to quantify the effects of stress on cotton maturity and fiber quality, and to estimate yield as a function of the relative partitioning of resources to competing sinks. This paper discusses the environmental factors affecting boll production and distribution, reviews methods of measuring and analyzing boll distribution, and discusses the comparative advantages and drawbacks of these methods. With the advent of advanced imaging technologies, this paper also discusses the potential transition from traditional methods to machine-based boll distribution measurements, the challenges associated with these technologies, and how continuous improvements in the baseline technologies being used in the different methods will translate to improved measurement capacities. Overall, major strides can still be made in the area of boll distribution measurement by combining the positive elements in the different studies described in this review to circumvent each of their respective limitations.

Non-optimal application of nitrogen (N) fertilizer in cotton (Gossypium hirsutum L.) production systems often results from a producer’s uncertainty in predicting the N rate that ensures maximum economic return. Residual soil nitrate-N (NO3-N) is also often unaccounted for in fertilizer management decisions. In this study, the lint yield and profitability of two cotton cultivars (FiberMax FM 958 and Deltapine DP 1646 B2XF) were compared across five N fertilizer treatments [0 kg ha−1 (control), 45 kg ha−1 (N-45), 90 kg ha−1 (N-90), 135 kg ha−1 (N-135), 180 kg ha−1 (N-180)] from 2018 to 2020. For both cultivars, additional N fertilizer on top of the control treatment did not increase the lint yield of cotton. For each year, both control and N-45 treatments resulted in the greatest revenue above variable costs (RAVC) values for all cultivars. The improved N partitioning efficiency in newer cultivars and the high levels of residual soil NO3-N allowed sustained plant growth and yield even with reduced N application. Overall, the results show the advantage of reducing N inputs in residual N-rich soils to maintain yield and increase profits. These findings are important in promoting more sustainable agricultural systems through reduced chemical inputs and maintained soil health.