Growing a crop in place of fallow may improve soil properties but result in reduced soil water and crop yields in semiarid regions. This study assessed the effect of replacing fallow in no‐till winter wheat (Triticum aestivum L.)–fallow with cover, forage, or grain crops on plant available water (PAW), wheat yield, grain quality, and profitability over 5 yr, from 2007 to 2012. Plant available water at wheat planting was reduced the most when the fallow period was the shortest (i.e., following grain crops) or when biomass production was the greatest. Winter and spring lentil (Lens culinaris Medik.) produced the least biomass, used the least soil water, and had the least negative effect on yield. For every 125 kg ha⁻¹ of cover or forage biomass grown, PAW was reduced by 1 mm, and for every millimeter of PAW, wheat yield was increased by 5.5 kg ha⁻¹. There was no difference in wheat yield whether the preceding crop was harvested for forage or left as standing cover. In years with above‐average precipitation, wheat yield was reduced 0 to 34% by growing a crop in place of fallow. However, in years with below‐average precipitation, wheat yield was reduced 40 to 70% without fallow. There was minimal negative impact on wheat yield growing a cover or forage crop in place of fallow if wheat yield potential was 3500 kg ha⁻¹ or greater. Net returns were reduced 50 to 100% by growing a cover crop. However, net returns were increased 26 to 240% by growing a forage crop. Integrating annual forages into the fallow period in semiarid regions has the greatest potential for adoption.

Long-term no-till (NT) systems in the semiarid central Great Plains of the United States require flexible management strategies to minimize the impacts of herbicide resistant (HR) kochia (Kochia scoparia L.) and tumble windmill grass (Chloris verticillata Nutt.) as well as nutrient stratification on soil and crop productivity. This study examined strategic tillage (ST) to control HR weeds and improve crop yields in an otherwise long-term NT cropping system. Treatments were three crop rotations: (1) continuous winter wheat (Triticum aestivum L.) (WW); (2) wheat-fallow (WF); and (3) wheat-grain sorghum (Sorghum bicolor L.)-fallow (WSF); as main plots. Subplots were reduced tillage (RT), continuous NT, and ST of NT. Results showed ST and RT treatments provided significant control of HR weeds. Soil water content at wheat planting was significantly less with RT compared to NT or ST. Strategic tillage did not affect wheat or grain sorghum yields, but RT decreased sorghum yields by 15% compared to NT. Increasing cropping intensity reduced wheat yields. Strategic tillage reduced bulk density and had no effect on aggregate size distribution or mean weight diameter (MWD) compared to NT though RT reduced the proportion of large macroaggregates and MWD. Similarly, ST compared to NT had no effect on soil organic carbon (SOC) or nitrogen (N) concentrations. Soil phosphorus (P) was not different among the tillage treatments though RT increased potassium (K) concentration near the soil surface. The SOC, MWD, and micronutrient availability were greatest with WW though it had significantly lower pH and K concentration. Our results suggest ST could provide a mitigation option for HR weeds in NT systems with little impact on crop yields and soil properties.

A long fallow period (∼15 mo) in a winter wheat (Triticum aestivum L.)–fallow rotation (W‐F) cropping system is meant to store soil water for the following crop but loss of soil quality, low precipitation use‐efficiency, and increased cost of fallow management are among its drawbacks. Replacing a portion of the fallow period with a short‐season cover crop may alleviate these drawbacks. The objectives of this study were to evaluate available soil water at planting (ASWP_cc), performance, management, and post‐cover‐crop fallow efficiency, and available soil water at winter wheat planting (ASWP_ww) of 12 short‐season cover crops. This field study was conducted from 2008 through 2011 at Garden City, KS. The experimental design was a randomized complete block with split‐split‐plot arrangement. Crop phases were main plot, cover‐crop species was the subplot, and cover‐crop management method (cover crop left standing or hayed) was the split‐split‐plot treatment. Results showed ASWP_cc was greater at spring cover‐crop planting than in the fall or winter cover crops. However, water use, productivity, and post‐cover‐crop fallow efficiency were greatest for sole winter triticale (×Triticosecale spp.) or winter legume–triticale mixtures. In addition, ASWP_ww was 4–27% more for cover crop left standing than hayed cover crops. Post‐cover‐crop precipitation storage was positively related to ASWP_ww but cover‐crop biomass had a negative linear relationship with ASWP_ww. We concluded that cover crops left standing stored more soil water than those hayed; however, forage use of the cover crop could provide a dual purpose and economic benefit to improve overall system profitability.

Forage cropping systems have greater precipitation use efficiency compared with cereal grains and oilseed cropping systems. However, information is limited to which forage species and forage rotation system increases productivity the most in the central Great Plains. The objective of this research was to identify the productivity and nutritive value of forage sorghum [FS, Sorghum bicolor (L.) Moench], winter triticale [WT, ×Triticosecale Wittm. ex A. Camus (Secale × Triticum)], and spring triticale (ST) crop rotations in the central Great Plains. The study was conducted from 2008 through 2011 at Garden City, Jetmore, and Tribune, KS. The experimental design was a randomized completed block with four crop rotation treatments: continuous FS–FS, continuous WT–WT, annual double‐crop WT/FS, and 2‐yr, double‐crop WT/FS–ST rotations. The annualized forage accumulation from WT/FS–ST rotation at Garden City, Jetmore, and Tribune were 30, 53, and 62% greater than annualized yields from the WT–WT rotation, respectively. The annualized forage accumulation from double crop WT/FS rotation were 55 and 148% greater than annualized forage accumulation from WT–WT rotation at Garden City and Jetmore. Overall productivity of a rotation was in the order WT/FS > WT/FS–ST or FS–FS > WT–WT. Despite its greater productivity, it was difficult to implement field operations (planting and harvesting) in the WT/FS rotation due to insufficient time in the growing season and because, often, there was little to no soil water available at planting. We concluded the WT/FS–ST rotation was less intense and more easily adoptable than the WT/FS rotation and has sufficient diversity to utilize resources better than continuous FS–FS or WT–WT rotations.

Adoption of cover crops is greatly dependent on their effect on the productivity of the main crops and profitability of system. The objective of this study was to quantify effects of spring fallow replacement grain, forage, and cover crops on winter wheat (Triticum aestivum L.) and grain sorghum (Sorghum bicolor) productivity and overall net return. This field study was conducted from 2013 through 2020 near Garden City, KS. Three phases of the wheat–sorghum–fallow (W‐S‐F) rotation were the main plots, and fallow and fallow replacement grain, forage, or cover crops were subplot treatments. Available soil water at planting (ASWP) of wheat was 58 to 81% less following forage and grain oat (Avena sativa L.) and triticale and ASWP of sorghum was 29% less following spring oat grain than fallow. Spring crops did not affect average wheat and sorghum yield, water use, or water productivity compared with fallow; likely because winter wheat yield potential over the study period was 3,500 kg ha⁻¹. Fallow replacement crops increased cost of production by 16 to 97% compared with fallow, and costs were greater for forage and grain crops than cover crops. However, gross returns of forage crops were greater than cover crops or grain crops. Net return was greatest for triticale forage than spring pea (Pisum sativum L.) grain. We concluded no significant effect of spring fallow replacements on wheat and sorghum yield, but greater net return from spring triticale forage because of greater forage productivity and low seed cost.