Access the full text.
Sign up today, get DeepDyve free for 14 days.
Loading next page...
/lp/wiley/single-and-multispecies-dual-purpose-cover-crop-productivity-nutritive-aJbIaOcd2r
- Publisher
- Wiley
- Copyright
- © 2022 Crop Science Society of America and American Society of Agronomy.
- eISSN
- 2639-6696
- DOI
- 10.1002/agg2.20275
- Publisher site
- See Article on Publisher Site
Abstract
AbbreviationsADFacid detergent fiberCCcover cropCPcrude proteinIVDMDin vitro dry matter digestibilityNDFneutral detergent fiberOToat and triticale mixtureOTPoat, triticale, and pea mixtureWSFwheat‐grain sorghum‐fallowINTRODUCTIONIncorporating cover crops (CCs) that have dual‐purpose use as forage diversifies a rotation system, increases productivity and precipitation use efficiency, leaves sufficient residue after harvest for soil protection, increases net return, and therefore it is ideal for the semiarid Great Plains (Holman et al., 2018; Holman, Assefa, & Obour, 2021; Nielsen et al., 2005). A significant increase in overall system productivity and profitability with CCs used as forage was reported for a wheat (Triticum aestivum L.)–fallow and wheat–sorghum [Sorghum bicolor (L.) Moench]–fallow (WSF) rotations (Holman, Assefa, & Obour, 2021; Holman, Obour, & Assefa, 2021a; Holman et al., 2022). Others also reported that an all‐forage‐crop rotation had the greatest net income, followed by a mixed grain and forage crop rotation system, compared with only grain‐based crop rotation (Nielsen et al., 2016). Growing forages in the crop rotation enable increased cropping intensity and increased profitability (Holman, Obour, & Assefa, 2021b). However, what CC mixture optimizes productivity, nutritive value, and profitability the best will be a continuous research gap that should be evaluated based on available CCs adapted across locations.A WSF rotation has two long fallow periods between planting and harvesting of the two (wheat and sorghum) crops (Baumhardt et al., 2015). Such fallow periods are common in dryland crop rotation with the intention of reducing the risk of crop failure by storing soil water for the next crop (Schlegel & Havlin, 1997). However, the drawbacks of long fallow periods, such as the two 11‐to 12‐mo‐long fallow periods in WSF rotation, are soil quality degradation, erosion, low precipitation use efficiency, and lower systems return (Anderson et al., 1999; Sharratt et al., 2018). Replacing part of the fallow with CCs reduces the negative impacts of long fallow season. Previous research showed a reduction in soil erosion (Lu et al., 2000) and increases in soil organic matter, aeration, soil water infiltration, and soil water holding capacity (Blanco‐Canqui et al., 2013; Larson et al., 2001). Others have reported reduction in the amount of N fertilizer needed for main crop with legume CCs (Bergtold et al., 2012), and reduced weed population (Osipitan et al., 2018; Petrosino et al., 2015), among the benefits of replacing fallow with CCs.In addition to benefits to soil physical properties, soil nutrients, and weed suppression, CCs used for forage contribute to profitability of the system. Holman et al. (2018) reported a 26–240% increase in net return from forage fallow replacements CCs in a wheat–fallow system. Similarly, Plastina et al. (2018) reported an increase in net return for farmers that grazed CCs. The size of the profit from a dual‐purpose CC, however, depends on factors such as the forage species, productivity, nutritive value, and cost of production (Holman, Obour, & Assefa, 2021b). For example, forage multispecies CC may provide the most benefits from a CC than a single species CC (Chapagain et al., 2020). Other studies, on the other hand, reported no advantage of CC mixtures compared with single species (DeLaune et al., 2020; Holman et al., 2018; Nielsen et al., 2015). Holman et al. (2018) concluded that CC species with low seed cost and greater forage accumulation are more profitable in the semiarid Great Plains.Among other CCs, spring oat (Avena sativa L.) and spring triticale [×Triticosecale Wittm. ex A. Camus (Secale × Triticum)] are well adapted and researched as spring crop forage options in the central Great Plains (Holman et al., 2020; Obour et al., 2020; Ruis et al., 2019). Forage oat is cool‐season crop, highly nutritious and preferred by animals (Ayalew et al., 2019; Carr et al., 2004). Forage triticale also has good winter hardiness, productivity, and nutritive value (Ayalew et al., 2018; Holman et al., 2018; Kavanagh & Hall, 2015; Kim et al., 2017). However, information regarding productivity, nutritive value, and profitability of these two forages, their mixture, and multimixture species of these forage crops with others is limited. The objective of this research is, therefore, to quantify forage productivity, nutritive value, and profitability of spring‐planted single or mixed species forages in a WSF crop rotation.Core IdeasProductivity was 33–35% greater with sole triticale and oat–triticale mixture than with sole spring oat or cocktail.Multispecies mixtures had greater nutritive value compared with single species (oat or triticale).Net return was $100 ha−1 more for the oat–triticale compared with multispecies mixtures.Greater productivity, net return, and adequate nutritive value make triticale and oat–triticale mixture better cover crops.MATERIALS AND METHODSSite description and study designThis study was conducted from 2015 to 2017 at the Kansas State University Hearting Beason Ranch near Brownell, KS (38°38′23″ N, 99°44′45″ W; elevation 736 m asl). The soil at the study site is a Harney silt loam (fine, smectitic, mesic Typic Argiustolls) formed from loess material. The long‐term average (30 yr) annual precipitation at the study site was 560 mm. Prior to this study, the field had been managed as WSF with reduce tillage. Soil pH averaged 6.5, with 2.3% organic matter, 26 mg kg−1 P, and 10 mg kg−1 NO3–N in the top 0‐to‐15‐cm depth. The experimental design was a split‐plot randomized complete block with four replications. The main plots were three crop phases of the WSF rotation (wheat–sorghum–fallow, sorghum–fallow–wheat, and fallow–wheat–sorghum), and subplots were five spring‐planted CC treatments: (a) spring oat, (b) spring triticale, (c) oat and triticale mixture (OT, two‐species mixture), (d) oat, triticale and pea (Pisum sativum L.; OTP, three‐species mixture), and (e) oat, triticale, pea, radish (Raphanus sativus L.), turnips (Brassica campestris L.), and buckwheat (Fagopyrum esculentum Moench; six‐species mixture).Plot management, forage mass, and nutritive valueAll crop phases (wheat, sorghum, or fallow) of the WSF rotation were present in every year of the study. This design allows wheat, sorghum, and CC treatments to be implemented and evaluated in each year of the study. Each main plot was 36 m wide by 30.5 m long, and CC subplot treatments were 9.1 m wide by 30.5 m long. Winter wheat was planted the first week of October each year using a Great Plains no‐till drill (Great Plains Manufacturing) at 67 kg ha−1 and harvested the following year in early July. After winter wheat harvest, the plots were then planted to grain sorghum at 77,000 seeds ha−1 the first week of June and harvested in November. The CC treatments were planted by 15 March in the fallow period between grain sorghum harvest and planting the next winter wheat crop in the rotation. Seeding rates were 72 kg ha−1 for oat; 86 kg ha−1 for triticale; 36 kg ha−1 of oat and 43 kg ha−1 of triticale (OT mixture); 24 kg ha−1 of oat, 32 kg ha−1 of triticale and 45 kg ha−1 of pea (OTP); and 17 kg ha−1 of oat, 17 kg ha−1 of triticale, 17 kg ha−1 of pea, 2 kg ha−1 of radish, 2 kg ha−1 of turnip, and 5 kg ha−1 of buckwheat.The CCs were harvested at oat and triticale heading corresponding to Zadoks Growth Stages 51–59 (Zadoks et al., 1974) to determine forage accumulation and nutritive value. This growth stage was selected to optimize oat and triticale forage accumulation and nutritive value (Obour et al., 2019, 2020). Forage harvesting dates were 27 May 2015, 5 June 2016 and 7 June 2017. During each harvest, a 0.9‐m × 30.5‐m forage strip was harvested from the middle of each plot using a Carter plot forage harvester (Carter Manufacturing Company) to a 15‐cm stubble height. Whole‐plot sample weights were recorded, and subsamples were weighed and oven dried to determined dry matter produced. Oven‐dried samples were ground to pass through a 1‐mm mesh screen in a Wiley Mill (Thomas Scientific). The ground samples were sent to a commercial laboratory (Ward Laboratories, Kearney, NE) to determine forage nutritive value. The forage nutritive value parameters determined included crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and in vitro dry matter digestibility (IVDMD) using a Foss 6500 near‐infrared spectroscopy system (Foss Analytical Systems).Economic analysisEconomic profitability (net returns) were calculated as total revenue minus total costs for each treatment in each year. Total revenue was calculated as forage mass multiplied by price of hay. Field operations and input costs were estimated using 5‐yr average custom rate values published by Kansas State University Land Use Survey Program and the Kansas Department of Agriculture (AgManager, 2021). Cover crop hay prices were taken from the USDA Economic Research Services market reports (USDA‐ERS, 2021). Prices for hay were calculated on a per kg basis and averaged US$0.147 kg−1 over the study period. Total variable costs were calculated as the sum of the expenses for CC seed, planting, harvesting, hay swathing, and baling. All costs and revenue were calculated on a per‐hectare basis in U.S. dollars. The cost per kilogram of protein produced was computed as total variable costs per treatment divided by CP yield for each treatment.Statistical analysisData analysis was conducted in SAS 9.4 (SAS Institute). Spring CC treatment, year, and interaction effects on response variables (forage accumulation, forage nutritive value, cost of production, and return) were analyzed using PROC MIXED procedure. First, each response variable was modeled against fixed variable CC treatment, year, and their interaction with replication as a random effect variable. For a significant (α = .05) main effect, a mean separation test was conducted using Tukey's honest significant difference. Also, a simple linear relationship between forage accumulation and net return was investigated for using PROC REG procedure in SAS.RESULTSForage accumulationForage accumulation was significantly different among CC treatments in 2015 and 2016 (Table 1). In 2015, forage accumulation of OT mixture was significantly greater than cocktail treatment. There was no significant difference between other CC treatments. In 2016, triticale forage accumulation was greater than spring oat and OTP mixture. The OTP and cocktail treatments did not significantly differ from each other or with other treatments in 2016. Forage accumulation was not significantly different among CC treatments in 2017.1TABLECover crop forage accumulation for the years 2015–2017, average across years, and Type 3 test of fixed effectsForage accumulationVariable201520162017Avg.kg ha−1Cover crop treatmentCocktail2,510b2,648ab2,3172,492cSpring oat (oat)3,070ab2,111b2,3282,503cSpring oat–triticale mixture (OT)3,984a2,884ab3,2583,375aSpring oat–triticale–pea mixture (OTP)2,823ab2,289b3,0872,733bcTriticale3,419ab3,730a2,8663,338abHSD1,3801,401NS642Year20153,16120162,73220172,771HSDNSType 3 test of fixed effectsTreatment (T).0429.0242.1715.0107Year (Y)–––.1735Y × T–––.3913Note. HSD, honest significant difference; NS, not significant. Within a column among treatments or years, means that share the same letter or those that have no letter are not significantly different (p = .05).Overall, across years, the OT mixture treatment forage accumulation was the greatest, followed by triticale, with no significant difference between the two. The forage accumulation of cocktail and spring oat treatments was the least among CC treatments. The main effect of year and year × treatment interaction effects were not significant for forage accumulation (Table 1).Nutritive valueThe two‐way interaction between treatments and year had significant effect on CP concentration (Table 2). In 2015, OTP mixture had greater CP concentration compared with single oat and OT mixture treatments, with no significant difference between cocktail and triticale (Figure 1). In 2016, cocktail treatment had greater CP concentration compared with single oat and OT mixture, again with no significant differences with remaining treatments. There was no significant difference in CP concentration between treatments in 2017. Crude protein concentrations were less in 2016 and 2017 because of little residual N, resulting in visible N deficiency and reduced CP. Average CP was 177 g kg−1 in 2015 with relatively better flush growth (Table 2). Across years, CP concentration was least with the OT mixture compared with the other CC treatments.2TABLECover crop nutritive value (i.e., crude protein [CP], acid detergent fiber [ADF], neutral detergent fiber [NDF], and in vitro dry matter [IVDM] concentration) by treatment and year and Type 3 test of fixed effectsConcentrationVariableCPADFNDFIVDMg kg−1Cover crop treatmentCocktail130ab372ab618b738aSpring oat (oat)119ab371b621b738aSpring oat–triticale mixture (OT)116b371b629ab727aSpring oat–triticale–pea mixture (OTP)134a371b615b737aTriticale121ab388a653a697bHSD15163127Year2015177a366b568c824a201691c386a641b678b2017103b371b673a681bHSD10112018Type 3 test of fixed effectsTreatment (T).0046.0311.0065.0002Year (Y)<.0001.0003<.0001<.0001Y × T.0117.5292.3388.4886Note. HSD, honest significant difference. Within a column among treatment or years, means that share the same letter or those that have no letter are not significantly different (p = .05).1FIGURECrude protein concentration of five spring cover crops treatments from 2015 through 2017 at Hays, KS. Trit, triticaleBoth the main effects of treatment and year had significant effect on ADF concentration (Table 2). Across years, ADF concentration was greatest in triticale compared with oat, OT, and OTP. Among years, ADF was greater in 2016 compared with both 2015 and 2017. Similarly, both the main effects of treatment and year significantly affected NDF concentration (Table 2). The NDF concentration was greatest in triticale compared with oat, cocktail, and OTP. Among years, NDF was the greatest in 2017 followed by 2016, and NDF concentration was the least in 2015. Unlike ADF and NDF, IVDMD concentration was least in triticale compared with all other treatments. The IVDMD concentration was greatest in 2015 compared with both 2016 and 2017 (Table 2).Cost of production and net returnTotal cost of production was greatest for sole triticale and triticale mixture CCs and least for sole spring oat (Figure 2). The variation in total cost was mainly due to variation in seed cost, and variable bale and stack costs. Seed cost varied across CC treatments. The OTP treatment ($81) had the greatest seed cost, and the least seed cost was the spring oat treatment ($43). Planting and swathing costs were same across treatments. Bale and stack cost were a function of yield, and it was less for spring oat, cocktail, and OTP treatments than for triticale and OT treatments (Figure 2).2FIGURESeed, planting, swathing costs (US$ ha−1); bale and stack cost (US$ kg−1); and total cost of production (US$ ha−1) of spring cover crops from 2015 through 2017 at Hays, KS. OT, oat–triticale mixture; OTP, oat–triticale–pea mixtureGross return was greatest for sole triticale and triticale mixed CCs compared with cocktail and sole spring oat treatments (Table 3). Gross return was not significantly different over the 3 yr. Net return was greatest for OT treatment compared with OTP and cocktail treatments (Table 3). There was no significant difference over the 3 yr in net return. There was a significant linear relationship between forage accumulation and net return for all treatments (Figure 3). Net return increased by $0.1 for each kg (ha)−1 increase in forage accumulation.3TABLEForage gross return, net return, crude protein yield, and cost per protein as affected by cover crop treatment and year and Type 3 test of fixed effectsVariableGross returnNet returnCrude protein yieldCost per proteinUS$ ha−1kg ha−1US$ kg−1Cover crop treatmentCocktail366b114b327ab0.88Spring oat (Oat)368b135ab307b0.91Spring oat–triticale mixture (OT)496a215a406a0.83Spring oat–triticale–pea mixture (OTP)402ab119b367ab0.92Triticale491a203ab404a0.79HSD1209096NSYear2015465184554a0.52c2016402142249b1.12a2017407146285b0.96bHSDNSNS640.11Type 3 test of fixed effectsTreatment (T).0107.0031.049.2381Year (Y).1736.1736<.0001<.0001Y × T.3913.3913.4277.1073Note. HSD, honest significant difference; NS, not significant. Within a column among treatments or years, means that share the same letter or those that have no letter are not significantly different (p = .05).3FIGUREForage accumulation and net revenue relations of spring cover crops from 2015 through 2017 at Hays, KS. Trit, triticaleCrude protein yield and cost per protein yieldCrude protein yield, a function of CP concentration and forage accumulation, was greater for triticale and OT treatments compared with spring oat (Table 3). Crude protein yield was greater in 2015 compared with both 2016 and 2017. Cost of production per protein yield, a function of CP yield and total cost of production, was unaffected by CC treatment (Table 3). Cost per protein yield was greatest in 2016, followed by 2017, and it was the least in 2015.DISCUSSIONCover crop forage accumulation was 33–35% greater in sole triticale and OT mixture compared with sole spring oat or cocktail treatments. These result suggest triticale or triticale‐dominated mixture productivity was greater compared with the sole spring oat mixture, or in the cocktail or OTP treatments where triticale's proportion was less. In line with our results, productivity of triticale CC was 182% more than that of oats in Garden City, KS (Holman, Assefa, & Obour, 2021; Holman, Obour, & Assefa, 2021a). In addition, triticale's potential productivity and adaptability over other CCs in drylands cropping systems was also reported by other studies (Ayalew et al., 2018; Ketterings et al., 2015; Roques et al., 2017).Greater nutritive values in CP and IVDMD indicate greater available energy and digestibility of the forage, and smaller values for ADF and NDF indicate greater dry matter intake and digestibility (Horrocks & Vallentine, 1999). In this study, multispecies mixtures (i.e., cocktail and OTP) had greater CP compared with sole oat CC treatment in 2 of the 3 yr, and their IVDMD was greater than triticale. Triticale had moderate levels of CP, the greatest ADF and NDF, and least IVDMD compared with most treatments. Therefore, cocktail and OTP forages have greater available energy, digestibility, and dry matter intake. Due to a relatively higher ADF and NDF and less IVDMD, triticale forage intake and digestibility could be less than the other treatments. Complementarity from the component crops in multimixture treatments often makes them better in nutritive value. A significantly greater nutritive value for mixture crops compared with sole triticale or sole oats, which we reported here, is in line with other findings (Holman, Assefa, & Obour, 2021; Karadag & Buyukburc, 2004).Unlike, nutritive value, net return was least for the two multispecies mixture CCs (cocktail and OTP). Multispecies mixtures had the greatest cost of production, mainly because of higher seed cost. Net return was greatest for the OT treatment because this treatment combines oat, which has least production cost, and triticale, which has greatest gross return due to its productivity. A greater net return from oat and triticale reported in the current study agrees with Holman et al. (2018), who concluded that fallow replacement CCs with greater forage mass and low seed cost were the most economically viable options for potential use as dual‐purpose CCs in semiarid regions. Cost of production of CP did not differ among treatments, and it ranged between $0.79 and 0.92 kg−1 protein, which is similar to cost of purchase per kilogram of protein for forage alfalfa feedstock. This suggests that spring‐planted CCs can provide forage with adequate nutritive value for livestock production.CONCLUSIONThe objective of this research was to quantify forage productivity, nutritive value, and profitability of spring‐planted single‐ or mixed‐species forages in a WSF crop rotation. Results showed CC forage accumulation was 33–35% greater in sole triticale and OT mixture compared with sole spring oat or cocktail treatments. Multispecies CCs mixtures, cocktail and OTP, had significantly greater available energy, digestibility, and dry matter intake based on measured CP, ADF, NDF, and IVDMD compared with single species (oat or triticale). Net return for the OT treatment was $100 ha−1 more compared with the multispecies mixtures (cocktail and OTP). We concluded sole triticale and OT mixture were better dual‐purpose spring CC alternatives than OTP, spring oat, or cocktail based on greater productivity and net return for the semiarid Great Plains.AUTHOR CONTRIBUTIONSAugustine Obour: Conceptualization; Methodology; Data curation; Funding acquisition; Investigation; Project administration; Supervision; Writing‐review & editing. John Holman: Conceptualization; Investigation; Methodology; Project administration; Writing‐review & editing. Yared Assefa: Formal analysis; Writing‐original draft; Writing‐review & editing.CONFLICT OF INTERESTThe authors declare no conflict of interest.REFERENCESAgManager. (2021). Kansas custom rates 2020. Kansas Department of Agriculture and Kansas State University Land Use Survey Program. https://www.agmanager.info/machinery/papers/custom‐rates‐surveyAnderson, R. L., Bowman, R. A., Nielsen, D. C., Vigil, M. F., Aiken, R. M., & Benjamin, J. G. (1999). Alternative crop rotations for the central Great Plains. Journal of Production Agriculture, 12, 95–99. https://doi.org/10.2134/jpa1999.0095Ayalew, H., Anderson, J. D., Kumssa, T. T., Maulana, F., & Ma, X.‐F. (2019). Screening oat germplasm for better adaptation to cold stress in the southern Great Plains of the United States. Journal of Agronomy and Crop Science, 205, 213–219. https://doi.org/10.1111/jac.12318Ayalew, H., Kumssa, T. T., Butler, T. J., & Ma, X.‐F. (2018). Triticale improvement for forage and cover crop uses in the southern Great Plains of the United States. Frontier in Plant Science, 9, 1130. https://doi.org/10.3389/fpls.2018.01130Baumhardt, R., Stewart, B., & Sainju, U. (2015). North American soil degradation: Processes, practices, and mitigating strategies. Sustainability (Switzerland), 7, 2936–2960. https://doi.org/10.3390/su7032936Bergtold, J. S., Duffy, P. A., Hite, D., & Raper, R. L. (2012). Demographic and management factors affecting the adoption and perceived yield benefit of winter cover crops in the Southeast. Journal of Agricultural and Applied Economics, 44, 1–18. https://doi.org/10.1017/S1074070800000195Blanco‐Canqui, H., Holman, J. D., Schlegel, A. J., Tatarko, J., & Shaver, T. M. (2013). Replacing fallow with cover crops in a semiarid soil: Effects on soil properties. Soil Science Society of America Journal, 77, 1026–1034. https://doi.org/10.2136/sssaj2013.01.0006Carr, P. M., Horsley, R. D., & Poland, W. W. (2004). Barley, oat, and cereal‐pea mixtures as dryland forages in the northern Great Plains. Agronomy Journal, 96, 677–684. https://doi.org/10.2134/agronj2004.0677Chapagain, T., Lee, E. A., & Raizada, M. N. (2020). The potential of multi‐species mixtures to diversify cover crop benefits. Sustainability, 12, 2058. https://doi.org/10.3390/su12052058DeLaune, P. B., Mubvumba, P., Fan, Y., & Bevers, S. (2020). Agronomic and economic impacts of cover crops in Texas Rolling Plains cotton. Agrosystems, Geosciences & Environment, 3, e20027. https://doi.org/10.1002/agg2.20027Holman, J. D., Arnet, K., Dille, J., Maxwell, S., Obour, A., Roberts, T., Roozeboom, K., & Schlegel, A. (2018). Can cover or forage crops replace fallow in the semiarid Central Great Plains? Crop Science, 58, 932–944. https://doi.org/10.2135/cropsci2017.05.0324Holman, J. D., Assefa, Y., & Obour, A. K. (2021). Cover crop water use and productivity in the high plains wheat‐fallow crop rotation. Crop Science, 61(2), 1374–1385. https://doi.org/10.1002/csc2.20365Holman, J. D., Obour, A. K., & Assefa, Y. (2021a). Fallow replacement cover crops in a semi‐arid High Plains cropping system. Crop Science, 61, 3799–3814. https://doi.org/10.1002/csc2.20543Holman, J. D., Obour, A. K., & Assefa, Y. (2021b). Rotation and tillage effects on forage cropping systems productivity and resource use efficiency. Crop Science, 61, 3830–3843. https://doi.org/10.1002/csc2.20565Holman, J. D., Obour, A. K., & Assefa, Y. (2022). Productivity and profitability with fallow replacement forage, grain, and cover crops in W‐S‐F rotation. Crop Science, 62, 913–927. https://doi.org/10.1002/csc2.20670Holman, J. D., Schlegel, A., Obour, A. K., & Assefa, Y. (2020). Dryland cropping system impact on forage accumulation, nutritive value, and rainfall use efficiency. Crop Science, 60, 3395–3409. https://doi.org/10.1002/csc2.20251Horrocks, R. D., & Vallentine, J. F. (1999). Harvested forages. Academic Press.Karadag, Y., & Buyukburc, U. (2004). Forage qualities forage yields and seed yields of some legume‐triticale mixtures under rainfed conditions. Acta Agriculturae Scandinavica, Section B: Soil and Plant Science, 54, 140–148. https://doi.org/10.1080/09064710310015481Kavanagh, V., & Hall, L. (2015). Biology and biosafety. In Eudes F. (Ed.), Triticale (pp. 3–13). Springer.Ketterings, Q. M., Swink, S. N., Duiker, S. W., Czymmek, K. J., Beegle, D. B., & Cox, W. J. (2015). Integrating cover crops for nitrogen management in corn systems on northeastern U.S. dairies. Agronomy Journal, 107, 1365–1376. https://doi.org/10.2134/agronj14.0385Kim, K. S., Anderson, J. D., Webb, S. L., Newell, M. A., & Butler, T. J. (2017). Variation in winter forage production of for small grain species‐oat, rye, triticale, and wheat. Pakistan Journal of Botany, 49, 553–559.Larson, J., Roberts, R., Jaenicke, E., & Tyler, D. (2001). Profit maximizing nitrogen fertilization rates for alternative tillage and winter cover systems. Journal of Cotton Science, 5, 156–168.Lu, Y.‐C., Watkins, K. B., Teasdale, J. R., & Abdul‐Baki, A. A. (2000). Cover crops in sustainable food production. Food Reviews International, 16, 121–157. https://doi.org/10.1081/FRI‐100100285Nielsen, D. C., Lyon, D. J., Hergert, G. W., Higgins, R. K., Calderón, F. J., & Vigil, M. F. (2015). Cover crop mixtures do not use water differently than single‐species plantings. Agronomy Journal, 107, 1025–1038. https://doi.org/10.2134/agronj14.0504Nielsen, D. C., Unger, P. W., & Miller, P. R. (2005). Efficient water use in dryland cropping systems in the Great Plains. Agronomy Journal, 97, 364–372. https://doi.org/10.2134/agronj2005.0364Nielsen, D. C., Vigil, M. F., & Hansen, N. C. (2016). Evaluating potential dryland cropping systems adapted to climate change in the central Great Plains. Agronomy Journal, 108, 2391–2405. https://doi.org/10.2134/agronj2016.07.0406Obour, A. K., Holman, J. D., & Schlegel, A. J. (2019). Seeding rate and nitrogen application effects on oat forage yield and nutritive value. Journal Plant Nutrition, 42, 1452–1460. https://doi.org/10.1080/01904167.2019.1617311Obour, A. K., Holman, J. D., & Schlegel, A. J. (2020). Spring triticale forage responses to seeding rate and nitrogen application. Agrosystem, Geoscience, and Environment, 3, e20053. https://doi.org/10.1002/agg2.20053Osipitan, O. A., Dille, J. A., Assefa, Y., & Knezevic, S. Z. (2018). Cover crop for early season weed suppression in crops: Systematic review and meta‐Analysis. Agronomy Journal, 110, 2211–2221. https://doi.org/10.2134/agronj2017.12.0752Plastina, A., Liu, F., Sawadgo, W., Miguez, F. E., Carlson, S., & Marcillo, G. (2018). Annual net returns to cover crops in Iowa. Journal of Applied Farm Economics, 2, 19–36. https://doi.org/10.7771/2331‐9151.1030Petrosino, J. S., Dille, J. A., Holman, J. D., & Roozeboom, K. L. (2015). Kochia suppression with cover crops in southwestern Kansas. Crop, Forage and Turfgrass Management, 1, 1–8. https://doi.org/10.2134/cftm2014.0078Roques, S. E., Kindred, D. R., & Clarke, S. (2017). Triticale out‐performs wheat on range of UK soils with a similar nitrogen requirement. Journal of Agricultural Science, 155, 261–281. https://doi.org/10.1017/S0021859616000356Ruis, S. J., Blanco‐Canqui, H., Creech, C. F., Koehler‐Cole, K., Elmore, R. W., & Francis, C. A. (2019). Cover crop biomass production in temperate agroecozones. Agronomy Journal, 111, 1535–1551. https://doi.org/10.2134/agronj2018.08.0535Schlegel, A. J., & Havlin, J. L. (1997). Green fallow for the central plains. Agronomy Journal, 89, 762–767. https://doi.org/10.2134/agronj1997.00021962008900050009xSharratt, B. S., Kennedy, A. C., Hansen, J. C., & Schillinger, W. F. (2018). Soil carbon loss by wind erosion of summer fallow fields in Washington's dryland wheat region. Soil Science Society of America Journal, 82(6), 1551–1558. https://doi.org/10.2136/sssaj2018.06.0214USDA‐ERS. (2021). Commodity cost and returns. Economic Research Service. https://www.ers.usda.gov/data‐products/Zadoks, J. C., Chang, T. T., & Konzak, C. F. (1974). A decimal code for the growth stages of cereals. Weed Research, 14, 415–421. https://doi.org/10.1111/j.1365‐3180.1974.tb01084.x
Journal
"Agrosystems, Geosciences & Environment" – Wiley
Published: Jan 1, 2022