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.

Grazing or haying dual-purpose cover crops (CCs) could provide an economic benefit to offset potential lost revenue when grain crop yields are decreased after CCs in dry years. However, there is concern that removing CC biomass could limit the beneficial effects of CCs for soil health and that root-limiting soil compaction may occur with grazing on no-till (NT) fields. Occasional tillage (OT) can be used to mitigate soil compaction caused from grazing CCs. The objectives of this study were to determine dual-purpose CC management and occasional tillage (OT) effects on plant-available water (PAW), crop yields, net returns, and soil properties in an NT dryland crop­ping system. This study was initiated in 2015 near Brownell, KS, with CCs grown in place of fallow and either hayed, grazed, or left standing. Half of each plot was tilled with a sweep plow once every three years ahead of wheat planting while the other half remained NT. Experimental design was a split-split-plot randomized complete block with four replications with all phases of the rotation present every year. Results showed that CC biomass averaged 2,800 lb/a. Grazing removed 40% of the available forage while haying removed 70%. Profile PAW at wheat planting was greater with fallow than with CCs but unaffected by tillage. Average wheat yield was unaffected by fallow management or tillage. Net returns were in the order of grazed CCs > hayed CCs > fallow = standing CCs but were unaffected by tillage on average. Fallow management had no effect on soil bulk density, which was slightly less with OT than NT. Bulk soil and particulate organic carbon were unaffected by fallow management or tillage. However, the mean weight diameter of water-stable aggregates was greater with CCs than with fallow but unaffected by tillage. Wind-erodible fraction was unaffected by fallow management but increased with OT compared to NT. These results suggest that dual-purpose CCs can provide forage for livestock, increase soil aggregate stability, maintain average crop yields, and increase net returns in NT systems. If OT is necessary to correct root-limiting soil compaction, PAW, crop yields, net returns, and soil proper­ties are generally unaffected compared to long-term NT.

Replacing fallow with dual-purpose cover crops (CCs) can increase the profitability of dryland crop rotations in the semi-arid Great Plains. Little research information is available on CC mixtures that optimize productivity and profitability in dryland environments. Field experiments were conducted from 2015 to 2017 at the Kansas State University Hearting Beason (HB) Ranch near Brownell, KS, to quantify forage productivity, nutritive value, and profitability of spring-planted single or mixed species CCs in a winter wheat-grain sorghum-fallow (WSF) crop rotation. The CC treatments were implemented in the fallow phase ahead of winter wheat planting. Treatments were five spring-planted CC treatments: (1) spring oat; (2) spring triticale; (3) oat and triticale mixture (OT, two-species mixture); (3) oat, triticale, and pea (OTP, three-species mixture); and (5) oat, triticale, pea, radish, turnips, and buckwheat (cocktail, six-species mixture), and chemical fallow. Results showed that CC forage accumulation was 33% to 35% greater in sole triticale and OT mixture compared with sole spring oat or cocktail treatments. Multispecies mixtures, cocktail, and OTP had significantly greater available energy, digestibility, and dry matter intake based on measured CP, ADF, NDF, and in vitro dry matter digestibility (IVDMD) compared with single CC species (oat or triticale). Net return was directly proportional to CC forage accumulation. Averaged across years, net return was $40/a greater for the OT treatment compared with the multi-species mixtures. Our results suggest that simple CC mixtures with greater forage accumulation (for example, sole triticale and OT mixture) are better dual-purpose CC alternatives for the semi-arid Great Plains.

Grazing cover crops (CCs) could provide an economic benefit to offset potential lost revenue when grain crop yields are decreased after CCs in dry years. However, there is limited guidance on the optimum biomass removal rate that balances soil health and grazing goals. An on-farm study was established in fall 2022 on a 50-acre producer field in Russell County, KS, to investigate the effects of CC biomass removal with cattle grazing on soil health parameters and grain crop yields, and profitability in no-till (NT) dryland cropping systems. The study design was a randomized complete block with three treatments and four replications. The treatments included ungrazed CCs, take-half-leave-half (T-H-L-H, 50% biomass removal), and graze-out (G-O, 90% biomass removal). Averaged across 2023-2024, the T-H-L-H and G-O significantly reduced CC residue amount, height, and residue cover when compared to ungrazed CCs. Cover crop management had no significant effect on soil organic carbon and particulate organic matter. However, phosphorus (P) concentrations were reduced by T-H-L-H and G-O when compared to ungrazed CCs, likely due to purposefully avoiding sampling near manure piles in the grazed plots that may be high in P. Take-half-leave-half and G-O also increased soil bulk density compared to ungrazed CCs. Soil penetration resistance, wind-erodible fraction, mean weight diameter of water-stable aggregates, time-to-runoff, and subsequent grain sorghum yields were unaffected by CC management. These results suggest that farmers and ranchers may be able to graze CCs at greater intensities than T-H-L-H to maximize livestock gains while maintaining soil health. This can increase adoption of CCs and benefit water quality protection and improvement efforts in reaching the goals of the approved 9 Element Watershed Plan through the Kansas Department of Health and Environment and the Environmental Protection Agency. However, these observations were made in a two-year study and under exceptional drought conditions, so further investigation will be necessary under conditions of average or above average precipitation when wet soils may be more susceptible to soil compaction by cattle hoof traffic.

Grazing cover crops (CCs) could provide an economic benefit to offset potential lost revenue when grain crop yields are decreased after CCs in dry years. However, there is limited guidance on the optimum biomass removal rate that balances soil health and grazing goals. An on-farm study was established in fall 2022 on a 50-a producer field in Russell Co., KS, to investigate the effects of CC biomass removal rates with cattle grazing on soil health parameters and grain crop yields, and profitability in no-till (NT) dryland cropping systems. The study design was a randomized complete block with three treatments and four replications. The treatments included ungrazed CCs, “take-half-leave-half” (T-H-L-H, 50% biomass removal), and “graze-out” (G-O, 90% biomass removal). Results showed that T-H-L-H and G-O significantly reduced CC residue amount and height compared to ungrazed CCs but maintained residue cover on the soil surface similar to ungrazed CCs. Cover crop management had no significant effect on soil organic carbon, particulate organic matter, nitrate-N, or P concentrations. However, T-H-L-H somewhat increased soil bulk density compared to ungrazed CCs, though both were similar to G-O. Soil penetration resistance, wind-erodible fraction, mean weight diameter of water stable aggregates, time-to-runoff, and subsequent grain sorghum yield were unaffected by CC management. These results suggest that farmers and ranchers may be able to graze CCs at greater intensities than T-H-L-H to maximize livestock gains while maintaining soil health. This approach could increase adoption of CCs and benefit water quality protection and improvement efforts in reaching the goals of the approved 9 Element Watershed Plan through the Kansas Department of Health and Environment and Environmental Protection Agency. However, these observations were made in a 1-year study and under exceptional drought conditions, so further inves­tigation will be necessary under conditions of average or above average precipitation when wet soils may be more susceptible to degradation by cattle hoof traffic.

Declining water well capacities across southwest Kansas and the High Plains have forced many producers to reassess crop selection for their irrigated acreage. One strategy that could stabilize irrigated acreage as well as on-farm economic returns and potentially reduce the rate of aquifer depletion is the incorporation of more drought-tolerant crops like cotton. However, in thermally-limited cottonproducing regions like southwest Kansas where the growing season is relatively short, regionally-focused management practices are essential to avoid yield and quality penalties due to the narrow production window between planting and physiological maturity. The objective of this study was to determine the impacts of planting date, seeding rate, variety, and irrigation level on cotton yield formation factors including square and boll initiation/position/retention as well as locks/boll, seeds/lock, and lint yield in the 2024 growing season at Garden City, KS. In this study, cotton yield components were most responsive to seeding rate followed by planting date and then variety maturity. Cotton yield components were least responsive to irrigation rate. Results showed stand density was slightly decreased under the high irrigation rate compared to the low irrigation rate and proportionally impacted by seeding rate in the order of 75,000 > 50,000 > 25,000 seeds/a. End of season bolls/plant were greater under the low seeding rate compared to the medium and high seeding rates. Locks/boll were unaffected by any treatments. Seeds/lock were greater with the early planting date than the late planting date. Cotton lint yield was greater with PHY 205 than PHY 332 and greater with the early planting date than with the late planting date. Lint yield was increased with increasing seeding rate in the order of 75,000 > 50,000 > 25,000 seeds/a. Plants/a was the only yield component significantly correlated with lint yield. Lint percent was greater with PHY 205 than PHY 332 and greater with the early planting date than the late planting date. Lint percent was greater with the highest seeding rate than the lowest seeding rate. These results underscore that successful stand establishment is essential to success with cotton in thermally-limited Kansas.