Forage Systems Research Articles

Biomass yield potential, feedstock quality, and nutrient removal of perennial buffer strips under continuous zero fertilizer application

Abstract. Perennial-based buffer strips have been promoted as having the potential for improving ecosystem services from riparian areas while producing biomass as livestock feed or as a bioenergy feedstock. Both biomass production and nutrient removal of buffer strips are substantially influenced by the vegetation types for the multipurpose perennial buffers. In this 2016–2019 study in western Illinois, two perennial cropping systems, including forage crops composed of cool-season grass mixtures (forage system) and bioenergy crops made up of warm-season grass mixtures (bioenergy system), were used to establish buffer strips for assessing biomass production, feedstock quality, nutrient removal, and buffer longevity. Treatments for this study reflecting agronomic practices included (1) two harvests occurring in summer (at anthesis) and fall (after complete senescence) and (2) one harvest in fall for the forage system (two-cut vs. one-cut forage) and (3) one fall harvest for the bioenergy system (one-cut bioenergy). Successively harvesting without any fertilizer input resulted in a yield decline in forage biomass over 3 years by approximately 30 % (6.3 to 4.4 Mg DM ha−1 (dry matter) with a rate of 1.0 Mg ha−1 yr−1) in the two-cut forage and by 35 % (4.9 to 3.2 Mg DM ha−1 with a rate of 0.9 Mg ha−1 yr−1) in the one-cut forage systems. The feed quality also decreased over the years by showing declined rates of 12.9 (crucial protein), 0.9 (calcium), 0.7 (copper), and 1.3 g kg−1 DM yr−1 (zinc). Empirical models predicted enteric CH4 emissions from cattle ranged from 225.7 to 242.6 g per cow per day based on the feed nutritive values. In contrast, bioenergy biomass yield increased by 27 % from 4.9 to 6.7 Mg DM ha−1 with a consistent quality (cellulose of ∼ 397.9 g kg−1; hemicellulose of ∼ 299.4 g kg−1), corresponding to the increased total theoretical ethanol yield from 1.8 × 103 to 2.4 × 103 L ha−1 (∼ 33 % increase). Annual nutrient removals of N, P, K, Ca, and Mg were significantly higher in the forage systems (e.g., two-cut: 52.6–106.9 kg N ha−1; one-cut: 44.5–84.1 kg N ha−1) than those in the bioenergy system (e.g., 25.9–34.4 kg N ha−1); however, the removal rate declined rapidly over 3 years (e.g., ∼ 49 % reduction) as the annual biomass yield declined in the forage systems. This on-farm field study demonstrated the potential of the perennial crop used as buffer strip options for biomass production and buffer sustainability at the edge of the field.

485 Impact of annual and perennial forage systems on forage biomass and quality, steer performance, and enteric methane emissions

Abstract Beef producers require forage options that provide adequate yield and high nutritive value, optimizing the production and sustainability of grazing operations. Few multiple year studies within Canada compare novel perennial and annual grass legume blends under grazing. This study evaluated the effects of perennial and annual forage systems on forage biomass and quality, grazing animal performance, and enteric emissions. Forage treatments included 1) AC Success hybrid bromegrass (Bromus riparius Rehm. × Bromus inermis Leyss.) + PS3006 alfalfa (Medicago sativa L.; HBG-ALF), 2) AC Armada meadow bromegrass (Bromus riparius Rehm.) + AAC Mountainview sainfoin (Onobrychis viciifolia Scop.; MBG-SF), 3) AC Hazlet fall rye (Secale cereale L.) + Frosty berseem clover (Trifolium alexandrinum L.; FR-CLOV), and 4) Winfred forage brassica (Brassica oleracea L.× Brassica rapa L.) + Gorilla forage brassica (Brassica napus L.) + 4010 pea (Pisum sativum L.) + CDC Austenson barley (Hordeum vulgare L.; BR-PE-BRAS). Yearling beef steers [n = 120, body weight (BW) = 397 ± 10 kg] were randomly allocated to 1 of 4 replicated (n = 3) forage systems for an average of 65 d grazing period amongst the 12 paddocks. Dry matter yield (DMY) was similar (P = 0.33) between BR-PE-BRAS (2,170 kg/ha) and HBG-ALF (1938 kg/ha), which were greater (P < 0.0001) than both MBG-SF (1030 kg/ha) and FR-CLOV (700 kg/ha) systems. Total digestible nutrient content (TDN) of FR-CLOV (63.6%) and BR-PEA-BRASS (62.0%) was greater (P < 0.0001) than both MBG-SF (51.7%) and HBG-ALF (49.3%) forages. Crude protein (CP) was greatest in FR-CLOV (15.2% P = 0.0012) intermediate in BR-PEA-BRASS (10.0%) and HBG-ALF (8.5%), and least in MBG-SF (6.6%). Steer performance was greatest when grazing HBG-ALF (87 kg/ha) paddocks, which was similar (P = 0.31) to FR-CLOV (62 kg/ha) and similar (P = 0.10) MBG-SF (51 kg/ha), but greater (P = 0.01) than BAR-PEA-BRASS (26 kg/ha). Enteric methane concentration from steers was the least when grazing BR-PE-BRAS (19.7g/kg DMI), followed by FR-CLOV (22.4g/kg DMI), MBG-SF (23.4g/kg DMI) and finally HBG-ALF (28.1g/kg DMI). In summary, BR-PE-BRAS and HBG-ALF forage systems provided the greatest DMY, while steer average daily gain (ADG) grazing HBG-ALF forage outperformed steers on BR-PE-BRAS paddocks. Forage energy and protein was greater in annual forage systems FR-CLOV and BR-PE-BRAS, compared with perennial forage systems. Enteric methane levels were the lowest in the steers grazing BR-PE-BRAS forage.

224 Yield and nutritive values of a polycrop and annual cereal monoculture used in winter swath grazing

Abstract This 3-yr study evaluated a comparative biomass yield and nutritive values of 2 forage systems: 1) a cereal monoculture (CDC-SO1 oats) and 2) a polycrops (PC) consisting of oat, brassicas (turnip and rape) and forage pea (4010) harvested at the hard dough (HD) stage for winter swath grazing purpose. A 12-ha field was divided into six, 2-ha paddocks, where each paddock was randomly assigned to 1 of 2 replicated (n = 3) forage systems. Forages were seeded in June and sampled for biomass yield and nutritive value at the soft dough (SD) and HD stages of oats. The seeding rate of oat monoculture (OM) was 157 kg/ha, while the PC was 45 kg/ha (oat), 11 kg/ha (forage pea) and 6 kg/ha (brassica). Forage samples were collected from a 0.6 m2 area at 24 pre-selected GPS points (4 per paddock), weighed and then oven-dried to a constant weight to determine DM yield. Data were analyzed using the PROC MIXED procedure of SAS and included treatment effects and treatments × stage interactions. Year was treated as a random effect due to climatic variations across years. For OM, there was a significant difference (P = 0.03) in biomass yield between SD (7,762.7 ± 1,217.9 kg/ha) and HD (8,902.8 ± 1,217.9 kg/ha) stages, while PC biomass yield did not differ (P = 0.94) between SD (5,922.4 ± 1,217.9 kg/ha) and HD (6,163.1±1,217.9 kg/ha) stages. The biomass yields between the two forage systems were different (P < 0.05) at the SD and HD stages. Crude protein (CP) concentration did not differ (P > 0.05) between the OM and PC at SD (10.4 vs 10.3%) and HD (8.9 vs 9.6%) stages. At the SD stage, significant differences (P < 0.05) between OM and the PC were observed for neutral detergent fiber (NDF, 50.9 vs 44.1%), calcium (0.2 vs 0.5%), phosphorus (0.2 vs 0.3%), and RFV-relative feed value (120.3 vs 142.2). Similarly, the starch (20.9 vs 16.5%), calcium (0.2 vs 0.5%), and phosphorus (0.2 vs 0.3%) values for OM and PC, respectively, also differed (P < 0.05) at the HD stage. Differences (P < 0.05) were observed between the SD and HD stages of OM for acid detergent fiber (ADF, 30.1 vs 27.0%), total digestible nutrient (TDN, 65.4 vs 67.9%), and starch (14.9 vs 20.9%) content, respectively. Study results suggest that swathing OM at the HD stage would be beneficial in terms of greater biomass yield without compromising quality, while PC can be harvested at either SD or HD stages based on the annual cereal component. Also, the lack of significant difference in the RFV, CP and TDN values between the PC and OM at the HD stage suggests that PC could be a viable alternative forage system for winter swath grazing.

Alfalfa‐bermudagrass mixtures managed under contrasting harvest strategies in the southeastern US

AbstractThe incorporation of dual‐purpose alfalfa (Medicago sativa L.) cultivars into bermudagrass (Cynodon spp.) is a viable option to extend the grazing season in Southern forage systems. However, data are limited on which harvest management strategy (HMS) optimizes the use of alfalfa‐bermudagrass (ABG) mixtures in the Southern US. A two‐year study evaluated ABG mixtures under three HMS [cut only (CO), graze only (GO), or cut and graze (CG)].in Headland, AL and Tifton, GA. Alfalfa‐bermudagrass mixtures utilized in this evaluation were ‘Bulldog 805’ alfalfa that was interseeded into ‘Tifton 85’ bermudagrass. Treatments were evaluated for forage, animal, and total system performance. Herbage accumulation varied by year and location (p < .01), but the number of harvests ultimately determined the total forage produced. Forage allowance was never limiting but did differ among treatments at Tifton, GA (p = .02). The CG HMS allowed for similar daily (p > .06) and liveweight gains (p > .56) on fewer days of grazing as compared to the GO treatments. The greater alfalfa percentage in the CG HMS translated to greater total digestible nutrients (TDN) and crude protein (CP), though not always statistically different. The CO HMS maximized system performance when evaluated for total gain (actual gains + predicted gains). However, the CG management allowed for more production opportunities across the season, thereby reducing economic risk. Future research should focus on evaluating the economic implications of introducing each HMS into ABG systems.

Agronomic and economic productivity of summer annual forage systems under different poultry litter application methods

AbstractPoultry litter (litter) is a nutrient dense fertilizer that increases nutritive value and yield in pastures in the mid‐southern US. Nutrient losses due to runoff and nitrogen volatilization are common when broadcasting litter. As such, incorporating litter below the soil surface (subsurface) was evaluated in comparison to broadcasting in 2021 and 2022 by quantifying yield and nutritive value of annual forages. The study was a randomized complete block design with three forage treatments—sorghum‐sudangrass only (Sorghum bicolor L.), cowpea only (Vigna unguiculata L.), and their mixture, and three litter application methods (broadcast, subsurface, and a no litter control). Litter was applied in 2021 only as biennial application is common to save on application cost. Nutritive analyses included neutral detergent fiber and crude protein (CP). Partial budgeting led to relative profitability estimates by accounting for yield and cost differences across treatments. In comparison to the second‐highest yielding forage mixture, sorghum‐sudangrass yielded 4.5%–18.4% more regardless of litter application method. The forage mixture did not improve forage nutritive value, as cowpea were vastly outcompeted and did not average more than 5% of the total forage harvested in mixtures. Cowpea yields did not benefit from litter application. Subsurface application resulted in 8%–10% greater CP content compared to no litter and broadcast litter, respectively, across all forage species. Sorghum‐sudangrass with subsurface applied litter earned nearly $70/acre more than sorghum‐sudangrass with broadcast litter, the next highest treatment combination, and, with lesser nutrient loss.

167 Use of plant growth-promoting rhizobacteria in bermudagrass systems of the Southeast US

Abstract Since the discovery of plant growth-promoting rhizobacteria (PGPR) in the mid-20th century, efforts have focused on utilizing them to reduce synthetic fertilizer usage and to improve the sustainability of agricultural systems. However, research in forage systems is lacking. The objective of the current study was to determine the use of PGPR in bermudagrass (Cynodon dactylon) forage systems in Central Alabama. The study was designed as a split plot and conducted at the E.V. Smith Research and Extension Center (Shorter, AL) and compared four levels of PGPR and five levels of nitrogen fertility rates. The PGPR included a negative control, Paenibacillus riograndensis DH44, Bacillus subtilis DH267, and UrtrishaN (Corteva Agriscience, Indianapolis, IN) were allocated to main plots. The strains of DH44 and DH267 were sprayed during each application at a population of 1-5 × 108 cfu/mL while UtrishaN (Corteva) was sprayed at a population of 3×107 cfu/mL with an activator at the rate of 0.25% vol/vol according to the manufacturer’s recommendations. The nitrogen fertilizer treatments were the subplot and were 25 and 50% of the recommended nitrogen for bermudagrass. The N treatments were as follows: negative control, 25% urea, 25% ammonium sulfate, 50% urea (F4), and 50% ammonium sulfate. Plots were treated with PGPR and N fertilizer starting on 11 May 2023. The forage harvest operation was conducted with at least 4 wk intervals depending on precipitation. After one year of the study, PGPR did not have any significant effect on forage biomass (1,209 kg /ha; P = 0.58). There was also no effect of N fertilizer (1,596 kg/ha; P = 0.35) or PGPR × N fertilizer interaction on forage biomass (1,408 kg/ha; P = 0.56). The lack of differences between positive and negative control plots indicates that growing conditions (i.e., lack of timely rainfall) during the first year of the study limited forage production for all treatments. The results from future years of this study will provide a more accurate conclusion on the use of PGPR with and without N fertilizer for bermudagrass systems.

160 Comparison of native to introduced mixed warm-season grass pastures on heifer weight gain and fecal egg count

Abstract The objective of this study was to compare summer body weight gain and fecal egg count change of spring weaned heifers grazing either native grass (NG; predominately big bluestem [Andropogon gerardii)) or mixed warm-season grass (MWS; predominately bermudagrass (Cynodon dactylon) and crabgrass (Digitaria sanguinalis)]. Pastures (n = 3 per treatment and 2.02 ha each) were continuously stocked with 10 heifers each in yr 1 and 2, respectively. All pastures received 56 kg/ha N mid-May. Grazing began at the end of May and all pastures were grazed for 84 d. Heifers were previously treated with an anthelmintic at weaning (benzimidazole in yr 1 and macrocyclic lactone plus benzimidazole in yr 2). Dependent responses were analyzed for the fixed effect of treatment, year, and their interaction and random effect of pasture. Pasture was the experimental unit. Fecal egg counts as eggs per gram were transformed to a log base 10 value (log10:epg). Average daily gain differed between treatments by year (P = 0.05). In yr 1, NG gained 0.22 kg/d more than MWS; whereas, in yr 2, NG gained 0.11 kg/d more than MWS. Heifers grazing NG were 15.9 ± 3.52 kg heavier than MWS by d 84 (P = 0.01). Change in fecal egg count differed by year (P < 0.001) and tended to be less for NG compared with MWS (P = 0.11). Native grass fecal egg count change was 45% of MWS. Impact of forage system on internal parasite load may be attributed to canopy structure. Native grasses averaged 67 and 81 ± 2.3 cm at the beginning of grazing in yr 1 and 2, respectively (P = 0.01). Native grass height in yr 1 and yr 2 was similar (P = 0.68) by wk 12 and averaged 41 ± 3.2 cm. By comparison, grazing in the MWS system would be much closer to the soil surface. Initial forage mass and forage mass change was greater in NG than MWS and differed by year (treatment × year P = 0.02 and 0.05, respectively). While this study demonstrated beneficial responses to grazing NG over MWS during summer months, further information regarding how these summer forage options compare under varied stocking rate and grazing duration is warranted.

Mixtures of Forage Species as Pasture for Dairy Ewes in a Mediterranean Environment

In Sicilian forage systems, the introduction of native self-seeding annual legumes can be beneficial in low-input farming. Intercropping would be a valuable strategy for implementing pasture resources in Sicilian forage systems during late spring. The aim of this study was to evaluate the effects on ewes’ milk production of continuous grazing with two different mixtures (i) sulla (Sulla coronarium L.), burr medic (Medicago polymorpha L.), and chicory (Cichorium intybus L.) (SuBuCh); and (ii) barrel medic (Medicago truncatula Gaertn.), snail medic (Medicago scutellata L.), and burr medic (BuSnBa). Twenty lactating ewes were homogeneously divided into four groups of five ewes. Each group was assigned to one of four 1500 m2 grazing sectors consisting of two replicates of SuBuCh and BuSnBa. Ewes fed with the SuBuCh mixture showed higher milk yield, higher protein (5.17 vs. 4.85%, p < 0.001) and casein content (4.02 vs. 3.73%, p < 0.001), lower urea content (37.70 vs. 45.38 mg dL−1, p < 0.001), and better clotting parameters compared to ewes grazing on the BuSnBa mixture. Finally, ewes in the SuBuCh group showed a smaller decrease in live weight at the end of the grazing period compared to BuSnBa ewes (−2.05 vs. −3.55 kg, respectively), although the difference did not reach a significant level. These preliminary one-year results seem to highlight the promising role of SuBuCh intercrop leading to a potential quantitative/qualitative improvement in grazing resources and the productive performance of grazing ewes in a semi-arid Mediterranean environment. However, it is of note that these outcomes might undergo variations when subjected to a prolonged trial extending beyond three years.

Ingestive behavior of beef calves on oat and ryegrass pasture intercropped with vetch at different seeding rates

The use of winter forage plants constitutes a procedure that optimizes cattle production, particularly in the subtropical region of Brazil. Understanding the relationship between forage species and grazing cattle, as well as their behavior within the environment, becomes crucial for a more efficient use of the forage. Therefore, the objective was to evaluate the ingestive behavior of beef calves in intercropped pastures of black oats, ryegrass, and vetch. A randomized block design was employed, with three area replications. The treatments resulted from the combination of ryegrass, black oats, and 0, 20, and 40 kg of vetch seed/ha. Twenty-seven Brangus calves kept under continuous grazing with variable stocking rates were used. Three daytime assessments of ingestive behavior were conducted. The forage systems did not influence the time spent on grazing, rumination, and other activities (P>0.05). However, as the grazing cycle progressed, the calves spent more time grazing and less time on other activities. The introduction of vetch into the forage mixture increased both the time and the number of chews during rumination (P<0.05). Towards the end of the grazing cycle, the calves needed to visit more feeding stations per minute and have a higher bite rate. Calves that grazed in higher vetch densities exhibited a greater number of steps between feeding stations, but only during the second period. The inclusion of vetch in conjunction with grasses only modifies the rumination patterns of calves, while the advancement of the phenological stage of the pasture leads to more evident changes in the ingestive behavior of grazing calves.

Enhancing the component intra- and interrelationship of Elymus nutans mono- and mixed sowing communities via adjusting sowing patterns in the Qinghai Tibetan Plateau

Spatial arrangement is a key factor in maintaining community yield and stability via regulating component intra-/interspecific competition in an alpine climate environment. A 2-yr field trial was conducted on the Qinghai Tibetan Plateau, including cross row (S_C), double row (S_D), single row (S_R), broadcast (M_B), dependent row (M_D) and independent row (M_I). Our results showed that S_C could avoid intraspecific competition by reasonable spatial arrangement, which favored the dominant component growth (1st year: leaf; 2nd year: stem and reproductive organ). For mixed communities, RII (relative interaction intensity) implied that interspecific competition also embodied on dominant component, and higher Elymus nutans component advantages seriously limited Onobrychis viciifolia's components growth in the 2nd year. More details displayed that E. nutans in M_B or M_D produced the maximum system yield via increasing leaf investment at the initial stages and stem investment after July 2019. Besides, M_I possessed lower component numbers than M_B and M_D in the unit area. PCA analysis revealed that component numbers or biomasses changed synchronously, besides the E. nutans of S_C, M_B, and M_D presented significant discrepancies compared to other treatments in September 2019, which verified the effect of sowing patterns on component growth (P < 0.05), but O. viciifolia in different sowing patterns was similar in the 2nd year. Considering the adaptability and production for the environment of the Qinghai Tibetan Plateau, S_C is recommended for the promoted effect on component biomasses. M_B and M_D, with the merit of spacing utilization as well as higher resistance to variation in seasonal growth conditions via optimizing interspecific relationships for mixed communities, are adapted for increasing yield via component harvesting. Our results unveiled the potential of optimizing spatial usage efficiency via controlling component growth characteristics and stressed the importance of dynamic change of dominant components to enhance forage system production in alpine regions.

Quality Production of Sainfoin Swards Challenged by Global Change in Mountain Areas in the Western Mediterranean

Legume-based livestock forage systems are widespread and socially relevant agroecosystems that are essential for delivering high-quality forage. Therefore, it is critical to determine how climate change and management might affect the functioning of forage agroecosystems. The objective of this study was to explore the potential of sainfoin swards under different management regimes by combining results from an experiment on species diversity effects on yield developed under extreme climatic conditions and a survey of sainfoin (Onobrychis viciifolia Scop.) swards and nutritive value in mountain regions in Catalonia, Western Mediterranean. Our results show that 12–59% of the variability in forage nutritive value parameters was accounted for by management. Young cattle-grazed swards showed higher nutrition quality that decreased faster than sheep-grazed or only mown swards. Mixing sainfoin with orchardgrass increased fiber content (e.g., +22% neutral detergent fiber) and decreased protein (−26%) and lignin (−11%) compared to sainfoin monocultures. However, under the extreme climatic conditions of the last three years, the only diversity effect found on yield was the identity of the species present. We propose that a combination of different sainfoin management regimes might be beneficial regionally for both quality forage production and overall biodiversity conservation, whereas traditional systems may be vulnerable to changing climatic conditions.

Influence of Pasture Stocking Method on Surface Runoff and Nutrient Loss in the US Upper Midwest

Grazing and hay forage crops reduce erosion compared to annual crops, but few studies have compared soil and nutrient loss among grazing systems compared to a control. We evaluated runoff water quality and nutrient loss among three grazing systems and a hay crop production field with manure application (control) using a paired watershed design. Four edge-of-field sites at a research farm in central Wisconsin were managed as hay during calibration (2013–2018) followed by a grazing treatment phase (2018–2020). Grazing treatments of different stocking methods included continuous stocking (CS), primary paddock stocking (PPS), and adaptive multi-paddock stocking (AMPS). Runoff, sediment, nitrogen (N), and phosphorus (P) loads were monitored year-round. Grazing increased average runoff volume by as much as 1.7-fold depending on stocking method and tended to decrease event mean N and P concentrations. CS had larger mean sediment (2.0-fold), total N (1.9-fold), and total P loads (1.2-fold) compared to the control and had the lowest average pasture forage mass. AMPS had lower N and P loss as a percentage of that applied from manure application/livestock excretion (1.3 and 1.6%, respectively) compared to the control (2.5 and 2.1%), PPS (2.5 and 2.6%), and CS (3.2 and 3.0%). Stocking method had a marked impact on nutrient loss in runoff from these systems, suggesting water quality models should account for pasture management, but nutrient losses from all perennial forage systems were small relative to previous data from annual cropping systems.

233 Fermentation Characteristics of Brassica and Wheat Mixed Silages

Abstract Winter feed management in the temperate regions of the U.S. primarily consists of stored or stockpiled grasses. Recently, forage brassica species have become popular additions to fall and winter grazing programs as an alternative feed source. Most all brassicas incorporated into forage systems are grazed; however, there may be more feeding options, such as fermenting them as silage or baleage. The objective of this project was to determine, utilizing a laboratory scale process, the feasibility and quality characteristics of two different brassica species alone or mixed with winter wheat. Forages were planted in 25.4 cm pots at a seeding rate comparable with field application. Three separate forage varieties were used: a hybrid forage rapeseed (RAPE), a forage turnip (TURNIP) and winter wheat (WHEAT). Along with these 3 varieties, two mixed forage treatments were utilized; a 3-way mix spaced and covered mimicking the effect of being planted with a drill (DRILL) and a 3-way mix randomly sprinkled and left uncovered mimicking a more random application (BROADCAST). Each of these 5 treatments were replicated 5 times and grown in the greenhouse for 76 d. At the conclusion of this growing period, forages were harvested 3 cm above the soil and immediately placed into vacuum-sealed bags. Bags were placed in a dark room and incubated for a total of 83 d. Following incubation, samples were analyzed for fermentation characteristics to determine quality of the ensiling process. Data were analyzed using the MIXED procedures of SAS. There was a treatment effect (P &amp;lt; 0.01) on the DM of the ensiled product whereby WHEAT (31.8%) was the greatest and BROADCAST (7.1%) was the least. The BROADCAST treatment had significantly (P &amp;lt; 0.01) greater ammonia concentration, as well as acetic acid (P &amp;lt; 0.05) concentration compared with all other treatments. No differences (P = 0.26) in pH were observed within the ensiled treatments. Overall, results of this trial suggest that it might be possible to use these brassica species as an ensiled feedstuff, though further testing is necessary to elucidate possible complications or limitations.

Correction to: Simulating Water Stress in Sorghum-Sudangrass Forage System with Different Nitrogen Sources and Tillage Practices

Correction to: Simulating Water Stress in Sorghum-Sudangrass Forage System with Different Nitrogen Sources and Tillage Practices

Framework to develop an open‐source forage data network to improve primary productivity and enhance system resiliency

AbstractData repositories using legacy data are needed to minimize research redundancy, enable knowledge synthesis, and optimize productivity and resiliency of agricultural systems. However, a framework is needed to develop an online searchable database to identify optimum systems for sustainable agricultural intensification and diversification, particularly for forages. Therefore, this paper outlines the development of a community‐driven forage database (Forage Data Hub) using legacy datasets encompassing multiple temporal and spatial scales and species to analyze system functionality and resiliency. Specific steps outlined included (1) developing minimum and preferred data requirements; (2) data standardization, structuring, and compilation; (3) creating a data thesaurus, data shapes, and data model; and (4) creating a web‐based system interface to facilitate database access. We demonstrate utility of curating these diverse datasets by quantifying forage system resiliency during extreme weather occurrences (relationship between standardized yields and yields during years receiving 25th percentile of the 30‐year normal precipitation) for three systems (monocrop annual, monocrop perennial, and mixed perennial) spanning 52,997 data entries (108 unique locations and 51 years). Overall, during low‐precipitation years, monocrop annual systems achieved 67% of their expected yield, while monocrop perennial systems achieved 93% and mixed perennial systems achieved 112% of potential yields. Therefore, diverse perennial systems were more resilient to climate‐related stresses compared to annual forage systems. Development of the US Forage Data Hub underscores the benefits of community‐driven data sharing and curation for a given commodity to provide system‐level sustainability assessments for identifying practices that promote ecological intensification and resiliency to climatic stochasticity.

Salinity and cultivar effects on alfalfa forage yield and nutritive value in a Mediterranean climate

AbstractBackgroundSoil and water salinity are increasing problems worldwide, causing significantly reduced crop yields. Alfalfa (Medicago sativa L.) is often listed as salt‐sensitive, but field testing of improved cultivars is limited. Forage systems and improved high‐quality alfalfa varieties are needed to enable crop production under high salinity (HS) conditions.MethodsThe objective of this study was to measure the yield and quality response of alfalfa to high saline conditions in the field and to document the relative saline tolerance of its varieties. HS irrigation water (electrical conductivity of water, or ECw 8.0–11.0 dS m−1) was applied to 33 nondormant alfalfa cultivars and were compared with low salinity (LS) treatments (ECw 0.5–1.2 dS m−1) over 4 years in a Mediterranean environment on a clay loam soil utilizing a split‐plot design. Crops were harvested seven to eight times per year, and the forage quality was measured on selected harvests utilizing near‐infrared spectroscopy.ResultsThe average yield loss due to HS treatment was 23.9% compared with LS treatment, but yields averaged 23.4 Mg ha−1 under HS over the 3 full years of production. This level of production is considered to be economically viable in this region. Differences in salinity tolerance between lines were identified in the field; individual cultivars lost 5%–35% of their LS yield when grown under HS conditions. Forage quality was significantly improved under HS versus LS conditions, but improvements were negatively correlated with biomass yield (R2 &gt; 0.81), similar to responses observed in drought‐stressed alfalfa.ConclusionsThese yield results confirm greenhouse studies, indicating that alfalfa is highly salt tolerant once established in the field, with potential for further improvement with tolerant cultivars. Salinity tolerance should be chosen based on total biomass yield as well as on the salinity tolerance index (HS yield relative to LS yield). Agronomic practices to mitigate salinity and sodicity are critical, along with improved cultivars.

Tillage, Manure, and Biochar Short-Term Effects on Soil Characteristics in Forage Systems

Manure, a globally used soil amendment, can contribute to excessive N and P runoff, leading to water pollution. Biochar (BC) shows promise in mitigating nutrient loss by retaining soil nutrients. However, there is limited research exploring the combined effects of tillage practices, biochar, manure, forage crops, and soil types on soil nutrient characteristics in a single field study. Our objectives are to determine if, in North Central Texas, differing soil types, soil amendments, forage crops, and tillage practices affect soil nutrients when applied short term, and whether correlations exist among soil nutrient characteristics as affected by soil amendments, tillage practices, and the presence of forage crops. The study encompasses three field sites with five factors, including soil types, manure rates, biochar rates, tillage practices, and forage crop types. Soil samples were assayed for pH, electrical conductivity (EC), macronutrients, and micronutrients. Data analyses involved variance analysis, Fisher’s tests, and Pearson’s correlations using R in Rstudio (the IDE). Microplots treated with manure (average 2.16 ppm) retained 60% greater average nitrate levels at the end of the growing season than those treated with a synthetic fertilizer (average 1.35 ppm) (p ≤ 0.05). Moderate and strong correlations were observed between EC and S (r (106) = 0.43, p &lt; 0.001 in loamy sand soil; r (106) = 0.80, p &lt; 0.001 in clay loam soil) and between nitrate and Zn, (r (106) = 0.36, p &lt; 0.001 in loamy sand soil; r (106) = 0.44, p &lt; 0.001 in sandy loam soil) across different soil types. Soil type (texture) emerged as the primary influencing factor on plant-available soil nutrients and characteristics, followed by manure application and tillage practices. The impact of BC and forage crop type varied depending on other experimental factors. Understanding the influence of soil type, amendment application, and tillage on soil nutrient characteristics can guide sustainable forage production practices and soil nutrient management strategies.

Simulating Water Stress in Sorghum-Sudangrass Forage System with Different Nitrogen Sources and Tillage Practices

Simulating Water Stress in Sorghum-Sudangrass Forage System with Different Nitrogen Sources and Tillage Practices

Influence of manure and tillage on soil carbon and soil organic matter in silt loam soils of corn–soybean–forage systems

AbstractIntroductionAn increasing number of farms in Northeast Ohio are being managed under reduced or conservation tillage practices, while those under conventional or intensive tillage are decreasing. Additionally, the use of on‐site farm manure among the growers is commonplace. Therefore, it is important to understand how the various management practices of these farms are impacting soil health, soil carbon stocks and crop yields.Materials and MethodsThis on‐farm study takes place in the temperate climate of the midwestern United States on a silt loam soil. It focuses on the impact of tillage (mouldboard plough [MP], vertical/chisel tillage [VT] and no‐tillage [NT]) and fertilizer (manure included or not) management practices on soil properties. Twelve agriculture fields and two woodland sites, for reference, on Canfield silt loam soils were selected for assessment in this project. Corn (Zea mays L.)–soybean (Glycine max L.) rotations and mixed forage Hayfields were the crops considered. Crop yields at each farm along with soil organic matter (SOM), total carbon (TC), total nitrogen (TN), bulk density, pH, soil test phosphorus (P), potassium (K) and sulphur (S) were assessed at two depths, 0–15 and 15–30 cm. Results of the first 2 years of the study (2020 and 2021) are presented here.ResultsAt the surface soil depth (0–15 cm), TC content was not different among cultivated fields (36 Mg ha−1), but was significantly less than Hayfields, which had the same amount of TC as the wood sites (58 Mg ha−1). There was no significant difference in soil test P, K or S due to tillage. Analysis of variance revealed no statistical difference due to fertilizer. At the soil surface depth, principal component analysis, supported by analysis of similarities (ANOSIM), determined that measurements of TC, TN and SOM distinguished a difference in Hayfields compared to cultivated fields (R‐statistic = 0.33; p = 0.001), but little difference when the 15–30 cm soil depth was considered (R‐statistic = 0.17; p = 0.001). ANOSIM also determined a slightly significant (R‐statistic = 0.065; p = 0.031) difference in fertilizer at the deeper soil depth. Correlation analysis revealed a strong positive relationship between SOM and corn grain yield (r = 0.59) and TN and corn grain yield (r = 0.39).ConclusionsThere was no significant loss of TC among increasing tillage intensities possibly due to the inclusion of manure fertilizer in tilled fields even though there were only slight statistical differences between fields that utilized manure and those that did not. The use of manure was not detrimental in terms of soil test P for most farms, but should be used judiciously. Inclusion of perennial crops such as hay in rotation with crop production can improve TC and TN content. Finally, increasing SOM could potentially increase corn grain yield, but no causal relationship has been determined yet.

A Living Lab approach for sustainable intensification of dairy production: A case study of an organic and a conventional farm in northern Italy

Working on feed production and feeding strategies is one of the key ways of mitigating dairy impacts and of increasing dairy efficiency and the nutritional quality of milk, all of which are priorities for global dairy sector stakeholders. Feed production, both on farm and off-farm, is one of the main contributors to dairy farm greenhouse gas (GHG) emissions, and it is known that the adopted feeding strategies influence farm nutrient balance, nutrient losses to the environment, and milk fatty acid profile. This study has been aimed at improving farm efficiency, environmental sustainability, and milk nutritional quality by acting on the management of the cropping system, and by promoting the on-farm production of feeds of high nutritional quality and high fiber digestibility in order to improve the self-sufficiency of metabolizable energy (ME) and protein (CP) for animal feeding. A multi-year study was conducted to analyze the shift in cropping system management on an organic farm and on a conventional dairy farm, considered as a “lighthouses”, and which were part of a Living Lab. Two 3-year pre-change periods (PRE) and two 3-year post-change periods (POST) with 2 years of transition were considered. The main actions performed on the management of the forage system involved changes in the crop destination, in the harvest schedule and in the conservation methods. All the data necessary to determine the dry matter (DM) yield, the forage quality, in terms of crude protein (CP), the metabolizable energy (ME), the nitrogen balance, and the carbon footprint of the two farms were measured or collected on farm. One kg of fat and protein corrected milk (FPCM) was used as a functional unit. In the POST periods, the milk production intensity (t FPCM/ha) improved and the ME and CP self-sufficiency of the heard increased on both farms. Both farms showed a 9.8% reduction of the Carbon Footprint (CF), and a reduction in the nitrogen surplus at the farm level. The amounts of C18:3 n-3 and n-3 fatty acids increased on both farms in the POST period. The results of this work show that it is possible to intensify milk production and mitigate the impacts of dairy farms by acting on the management of the forage system and on the feed strategies, using a synergistic Living Lab approach to achieve sustainable intensification.