Occasional Tillage in a Wheat-Sorghum- Fallow Rotation (original) (raw)
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Tillage Intensity in a Long-Term Wheat- Sorghum-Fallow Rotation
Kansas Agricultural Experiment Station Research Reports
Grain yields of wheat and grain sorghum increased with decreased tillage intensity in a wheat-sorghum-fallow (WSF) rotation. In 2015, available soil water at wheat planting was greater for no-till (NT) and reduced till (RT) than for conventional till (CT). Similarly, for grain sorghum in 2015, available soil water at planting was increased with NT or RT and least with CT. Averaged across the 15-yr study, available soil water at wheat and sorghum planting was similar for RT and NT and about 1 inch greater than CT. Averaged across the past 15 years, NT wheat yields were 5 bu/a greater than RT and 7 bu/a greater than CT. Grain sorghum yields in 2015 were 42 bu/a greater with long-term NT than short-term NT. Averaged across the past 15 years, sorghum yields with long-term NT have been nearly twice as great as short-term NT (64 vs. 35 bu/a).
Long-Term No-Till in a Wheat-Sorghum-Fallow Rotation
Kansas Agricultural Experiment Station Research Reports
Grain yields of wheat and grain sorghum increased with decreased tillage intensity in a wheat-sorghumfallow (WSF) rotation. In 2014, available soil water at wheat planting was 2 inches greater for no-till (NT) than for reduced-tillage (RT) or conventional tillage (CT). For grain sorghum in 2014, available soil water at planting was greatest with RT and least with CT. Averaged across the 14-year study, available soil water at wheat and sorghum planting was similar for RT and NT and about 1 inch greater than CT. Averaged across the past 14 years, NT wheat yields were 5 bu/a greater than RT and 7 bu/a greater than CT. Grain sorghum yields in 2014 were 22 bu/a greater with longterm NT than short-term NT. Averaged across the past 14 years, sorghum yields with long-term NT have been nearly twice as great as short-term NT (61 vs. 33 bu/a).
Soil and Tillage Research, 1998
On the Canadian prairies there has been a steady increase in no-till seeding coupled with more frequent cropping, facilitated by the greater use of snow management to increase stored soil water. Although no-till seeding can gradually improve soil conservation and soil quality, it may also increase the incidence of grassy weed infestations and thus cause more frequent use of costly herbicides, such as glyphosate. Our objective was to determine if no-till producers experiencing grassy weed problems could introduce pre-seeding tillage for a few years to more economically control perennial weeds, without adversely affecting grain yield and quality, and soil quality. An experiment in which spring wheat (Triticum aestivum L.) was grown for 9 years with no-tillage management on an Orthic Brown Chernozem (Typic Haplobroll) with treatments involving snow management and N rate, placement and timing, was converted to a study of pre-seeding shallow (5±7.5 cm) tillage with a cultivator, versus no-tillage, by replacing the N timing treatment in the tenth year. The experiment was then continued for three more years, during which we assessed the effect of tillage on weed populations, grain yield and N content, and on soil quality. Soil quality was also assessed following one more year during which the entire study site was summerfallowed and subjected to four tillage operations. Weed populations generally were not affected by tillage or snow management treatments, but differed among N rate and placement treatments, though not in a way that could be easily interpreted. Tillage had no effect on yield or grain N content. It increased the erodible fraction of soil (dry sieving), but did not affect wet aggregate stability. Neither microbial biomass C, nor C and N mineralization were affected by the change in tillage method. We conclude that the judicious use of shallow pre-seeding tillage in an otherwise no-till cropping system can be tolerated to manage persistent grassy weed problems without deleteriously in¯uencing soil quality, grain yield or protein. #
Soil and Tillage Research, 2007
Conventional tillage winter wheat (Triticum aestivum) (WW)-summer fallow reduces soil productivity and increases soil erosion. Conservation tillage management, together with intensive cropping may have the potential to reverse these sustainability concerns. The objective of this study was to determine the effects of conventional tillage (CT) and no-tillage (NT) systems on grain yield of long-term annual cropping of monoculture WW, spring wheat (SW), and spring barley (Hordeum vulgare) (SB) grown with or without fertilizer, in the Pacific Northwest region of the USA. In unfertilized crops, grain yield of WW, SW, and SB was 15%, 25%, and 50% higher, respectively, in CT than in NT plots, an indication of the involvement of yield limiting factors under the NT cropping system. When fertilized, there were no significant differences in grain yield of WW. Yields of SW and SB, however, remained 21% and 15% higher, respectively, in CT than in NT, an indication that factors other than fertility were involved. These results suggest that in order for NT management to be widely adopted by area growers, the yield-limiting factors need to be addressed. #
Strategic Tillage in Dryland No-Tillage Crop Production Systems
Kansas Agricultural Experiment Station Research Reports
Emerging challenges in continuous no-till (NT) systems require developing flexible management strategies that will minimize the impacts of herbicide resistant (HR) weeds and nutrient stratification on soil and crop productivity. This study evaluated the effectiveness of strategic tillage (ST) operations as an option to redistribute soil nutrients and acidity, control perennial grass and HR weeds, and improve crop yields following tillage of an otherwise long-term NT soil. Treatments were five crop rotations: 1) continuous winter wheat (WW); 2) wheat-fallow (WF); 3) wheat-sorghum-fallow (WSF); 4) continuous sorghum (SS); and 5) sorghum-fallow (SF) as main plots. Sub-plots were reduced tilled (RT), continuous NT, and ST of long-term NT. Grass and herbicide resistant weeds were reduced with tillage. Irrespective of crop rotation, soil water content at wheat planting was significantly less with RT treatments compared to NT or ST. Soil water content with NT was not different from that of ST under cropping systems with fallow (WF or WSF). Tillage (ST or RT) reduced soil water content at wheat planting in WW system. Winter wheat grain yields decreased with increasing cropping intensity, WF (26-48 bu/a) > WSF (22-33 bu/a) > WW (15-19 bu/a). Averaged across years and crop rotations, wheat yield with ST was 30 bu/a, which was greater than the NT (23 bu/a) or RT (28 bu/a) systems, mostly due to better weed control and increased nutrient availability. Sorghum grain yield over the 2 years with ST (63 bu/a) was not different from that of NT (61 bu/a), but were both greater than that of RT (54 bu/a). Increasing cropping intensity reduced sorghum grain yield, average grain yield with SF was 73 bu/a, similar to WSF (68 bu/a), but greater than SS (38 bu/a). Tillage had no effect on soil bulk density. However, increasing cropping intensity lowered the bulk density measured in the upper 0 to 2 in. of the soil. Tillage and crop rotation effects on soil organic matter (SOM), pH, and nutrient concentrations occurred only in the top 0-to 2-in. depth. The SOM, iron (Fe), and manganese (MN) concentrations were greater in soils under WW compared to WF or WSF. Soil pH and potassium (K) were least in soils under WW. The SOM concentration in the top 0 to 2 in. with NT was 3.34%, which was similar to that of soil under ST (3.02%) but both were greater than RT (2.65%). Nitrate-N concentration increased with ST but ammonium-N concentration was greatest in soils under NT. Our results suggest ST could provide a mitigation option for HR weeds in NT crop production with little impact on crop yields and soil chemical properties.
Agronomy Journal, 2015
Corn yield (Zea mays L.) and economic return with different tillage systems and crop rotations are highly influenced by regional soil and climate conditions. This study was conducted at seven locations in Iowa from 2003 to 2013. The experiment design was split-plot with tillage as the main factor, which included five tillage systems (no-tillage, NT; strip-tillage, ST; chisel plow, CP; deep rip, DR; and moldboard plow, MP).Three crop rotations of corn-soybean (Glycine max L.), C-S; corn-corn-soybean, C-C-S; and corn-corn, C-C were subplots in a completely randomized block design in four replications. The objectives were to: (i) investigate seasonal variability in corn yield as affected by tillage and crop rotation, (ii) identify appropriate tillage for each crop rotation and location, and (iii) evaluate the magnitude of crop rotation effect on corn yield. Corn yields varied from 2.5 to 15.8 Mg ha -1 with no detectable increase over time. The results showed northern locations have yield of 1.9 Mg ha -1 and economic return of US$329 ha -1 advantage over southern locations. Yield and economic returns for the three rotations were as follow: C-S > C-C-S > C-C. Yield and economic penalty were greater with NT than conventional tillage in the northern locations (poorly-drained soils) than locations with well-drained soils. The corn yield penalty associated with C-C was location specific and varied from 11 to 28%. The findings suggest a location specific adoption of tillage and crop rotation for achieving optimum yield.
Journal of Production Agriculture, 1990
Wheat (Triticum aestivum L.) in the central or southern Great Plains is grown in a 2-yr wheat-fallow (WF) cropping system or with grain sorghum [Sorghum bicolor (L.) Moench] in a 3-yr wheat-sorghum-fallow (WSF) system. Tillage during fallow causes loss of crop residue and soil water. Long-term studies were conducted at Garden City and Tribune, KS, to determine the effects of cropping system and reduced tillage on available soil water and yield of dryland winter wheat and grain sorghum. Conventional (CT), reduced (RT), minimum (MT), and notillage (NT) systems were compared in WF and WSF. These treatments also were compared with CT in sorghum-fallow (SF), continuous sorghum (SS), and continuous wheat (WW). Reductions in tillage resulted in increased available soil water and yield. Reduced tillage resulted in increased WF yields at both locations, while WSF wheat yields were increased at Tribune. Sorghum yields were more consistently increased by reduced tillage at Tribune. Sorghum-fallow yields were higher than WSF sorghum yields at Tribune. Wheat-fallow yields usually did not differ from WSF wheat yields at either location. Sorghum yields in WSF exceeded SS yields 67% of the time at Garden City. At Tribune, WSF-RT yields exceeded SS yields 73% of the time, while WSF-CT yields were no better or less than SS yields 60% of the time. Continuous wheat yields were less than other wheat yields 98% of the time. In terms of soil water storage and yield, the WSF system is appropriate for both locations, and is more effective when combined with reduced tillage, particularly at Tribune. HEAT is the most commonly grown dryland crop in the Great Plains. Fallowing is a common practice used to store water for the following wheat crop. The wheat-fallow cropping system produces one crop in 2 yr with a 15-mo fallow period between crops. Five to seven tillage operations are typically necessary during this period to control weeds. Excessive tillage results in soil water loss and destruction of virtually all residue from the preceding crop. Thus, the soil is subject to erosion by both wind and water. Herbicide use to replace tillage (chemical fallow) has resulted in increased soil water storage and increased crop yields (Fenster and Peterson, 1979; Fenster and Wicks, 1982). Tanaka (1986) found chemical fallow resulted in 37% more standing residue than with stubble mulch. Substantial reductions in erosion (Good and Smika, 1978) and weed growth (Greb and Zimdahl, 1980) have been reported when chemical fallow was practiced.
Occasional Tillage and Nitrogen Application Effects on Winter Wheat and Grain Sorghum Yield
Kansas Agricultural Experiment Station Research Reports
Occasional tillage ahead of winter wheat planting could alleviate herbicide-resistant weeds, redistribute soil acidification, and improve seedbed at wheat planting. The objective of this study is to determine occasional tillage and nitrogen (N) fertilizer application effects on winter wheat, and grain sorghum yields and soil quality in a wheat-sorghum-fallow cropping system. Treatments were three tillage practices: 1) continuous no-tillage (NT); 2) continuous reduced-tillage (RT); and 3) single tillage operation every 3 years (June-July) ahead of winter wheat planting [occasional tillage (OT)]. The sub-plot treatments were assigned to four N fertilizer rates (0, 40, 80 and 120 lb/a of N). Preliminary results showed tillage had no effect on winter wheat grain yield. Applying N fertilizer increased wheat yield, ranging from 21 bu/a with no N fertilizer to 29 bu/a when N fertilizer was applied at 120 lb/a of N. Tillage and N fertilizer effects on grain sorghum yield varied over the 2 years of the study. Grain sorghum yields in 2017 decreased with RT but tillage had no effect on sorghum yields in 2018. Averaged across tillage and years, sorghum grain yield was 54 bu/a with no N fertilizer and 84 bu/a when N was applied at 120 lb/a of N. Both sorghum and winter wheat grain yields obtained with 80 lb/a of N were not different from those with 120 lb/a of N, suggesting 80 lb/a of N may be adequate for both crops.