Crop, Forage and Turfgrass Management最新文献

Herbicides are one of the primary tools for vegetation management along roadsides. However, the drift of particles and vapors from herbicide applications along roadsides can cause damage and yield loss in adjacent sensitive crops. The objective of this research was to investigate the response of soybean [Glycine max (L.) Merr.] and tobacco (Nicotiana tabacum L.) to sublethal rates of five herbicides [sulfometuron-methyl, indaziflam, triclopyr, triclopyr + clopyralid, and 2,4-dichlorophenoxyacetic acid (2,4-D) + dichlorprop] commonly used along North Carolina roadsides. Each herbicide was applied at four rates (0.01×, 0.05×, 0.10×, and 1× of the field rate) and at six different timings (18, 12, and 6 weeks before planting or transplanting, at planting or transplanting, and 4 and 8 weeks after planting or transplanting). Field studies were conducted at the Sandhills Research Station near Jackson Springs, NC, in 2022 and 2023. In soybean, triclopyr applied post-planting caused the greatest injury and yield loss, up to 100% when applied at the full dose (1×), while indaziflam was most damaging at or before planting. In tobacco, triclopyr followed by 2,4-D + dichlorprop applied post-transplanting caused the greatest injury and height reduction, whereas indaziflam caused mild visual injury (≤28%) and minimal height reduction across all timings. Crop damage generally increased with rate; however, injury, height reduction, and yield loss were occasionally observed even at the lowest rate (0.01×). These findings demonstrate that herbicides commonly used for roadside vegetation management differ in their potential to injure soybean and tobacco crops, underscoring the importance of informed and cautious herbicide selection to minimize the risk of off-target injury when these crops are grown near roadsides.

Integrated crop–livestock systems are designed to enhance soil health attributes, thereby contributing to increased crop production and economic profitability. The objective of this research was to compare the effects on soil health of various soybean [Glycine max (L.) Merr.]–cover crop–livestock production systems. A field trial was conducted at the Coastal Plain Branch Experiment Station (CPBES) in Newton, MS, and the Prairie Research Unit (PRU) in Prairie, MS, from 2021 to 2023. Treatments included (a) conventional tillage soybean (CS), (b) no-till soybean + cereal rye (Secale cereale L.) cover crop, and (c) no-till soybean + grazed cereal rye cover crop (GC). Soil health analyses were conducted on samples collected biannually from each location. At CPBES, no biological parameters were affected by the treatment. At PRU, permanganate oxidizable carbon and soil organic matter were lowest for CS on the third and fourth sampling dates (both 5.6 ppm). Extractable P was higher in CS treatments at CPBES for all sampling dates. At PRU, extractable K was highest in GC treatments on three of the four sampling dates. At CPBES, penetration resistance was greatest in GC treatments across all sampling dates, while water-stable aggregate formation in GC treatments was greater than in CS treatments on the third and fourth sampling dates (third: 22.6 vs. 14.5 lb in.²; fourth: 27.6 vs. 20.2 lb in.²). No differences in the comprehensive assessment of soil health scores were observed at CPBES (p = 0.5003) or PRU (p = 0.0616), suggesting that, although differences in individual analyses may be present, the impact of grazed and ungrazed cover crop treatments was negligible on soil health during the experimental period.

Peanut (Arachis hypogaea L.) production contributes substantial organic matter and nutrients to subsequent rotations, but residue distribution by harvest equipment is often uneven. This study quantified peanut chaff distribution across 6-row combines at multiple sites in the Missouri Delta during 2023 and 2024. Vine and leaf residues were sampled at the left, center, and right swath positions, then dried and analyzed for nitrogen (N), phosphorus (P), and potassium (K) content. Leaf residue accumulated predominantly in the swath center (2350 lb ac⁻¹) compared with the left (813 lb ac⁻¹) and right (603 lb ac⁻¹), resulting in greater nutrient deposition in central rows (N: 63 vs. 21–26 lb ac⁻¹; P: 4.5 vs. 1.6–1.9 lb ac⁻¹; K: 78 vs. 31–36 lb ac⁻¹). Vine residue showed similar but less pronounced patterns. These findings demonstrate that peanut combines produce nonuniform residue and nutrient return at harvest. Although crop responses were not directly measured, spatial variability in residue may influence early growth and nutrient availability for rotational crops. Strategies such as equipment retrofits, postharvest redistribution, or cover crop integration could reduce intra-field variability and optimize rotational benefits.

Producers in the lower Midwest United States often plant soybean [Glycine max (L.) Merr.] as a double crop following the harvest of wheat (Triticum aestivum L.), but yields are lower than those of full-season soybean. An alternative legume crop commonly grown in the upper Midwest and Western United States is dry bean (Phaseolus vulgaris L.), but no published data are available on the best-suited market classes and cultivars for production in the lower Midwest. Therefore, a 2-year study was conducted in central Missouri in 2013–2014 to test representative cultivars from eight dry bean market classes for grain yield and leaf greenness. Grain yields ranged from 754 to 2548 lb ac⁻¹, with cultivars from the Great Northern white and black-market classes producing higher yields than the five lowest yielding cultivars. Leaf greenness was greater in the small red, pink, and pinto cultivars than in the white kidney, black, Great Northern, and small red kidney cultivars and did not correspond to grain yield. In general, dry bean in Missouri have potential yields comparable to those in the upper Midwest. Producers should consider the Great Northern white, black, small red, and pink market classes. Further research is necessary to test a broader range of cultivars across diverse environments to provide better agronomic recommendations.

Aeration, when combined with sand topdressing, introduces sand into putting green root zones. More intensive aeration during a single event is becoming increasingly common to reduce the number of aeration events during a year. The goal of this study was to compare different aerator-pass frequencies with 0.375- or 0.625-inch (diameter) solid tines during a single aeration event. Experiments were conducted on cool-season putting greens at Chambers Bay Golf Course and Tacoma Country and Golf Club during three aeration events in 2023 and 2024. Six aeration treatments included solid-tine aeration with 0.375- or 0.625-inch tines for one (1×), two (2×), or three (3×) passes using an aerator set to a 3-inch depth on 2-inch centers. An uncultivated control was included for comparison. All sand additions and removals were weighed to determine the amount of sand incorporated into each plot. Total organic matter was determined for depths of 1 and 3 inches before and after aeration. Sand incorporation generally increased with aeration tine size and with the number of aerator passes and was similar between 2× and 3× frequencies with 0.375-inch tine aeration and 1× 0.625-inch tine aeration. Total organic matter from a depth of 1 inch ranged from ∼6% to 9% at each golf course in Spring 2023 and increased through Spring 2024 only for untreated plots. Superintendents can use multiple passes with smaller tines to achieve as much sand incorporation and organic matter mitigation as traditional, “aggressive” aeration does with a single pass from larger tines.

Managing grazing efficiency requires reliable and practical tools to estimate forage mass. Traditional methods like clipping, though accurate, are time consuming and labor intensive. In this study, two imaging tools, Canopeo and the Crop Canopy Image Analyzer (CCIA), were evaluated for their efficacy in estimating the forage mass of cereal rye (Secale cereale L.) using smartphone images collected under rotational grazing conditions in Nebraska, USA. Over 2 years, 400 forage samples were collected. Forage images were taken using smartphones before clipping, and canopy cover was estimated from these images using Canopeo and the CCIA tool. Regression analysis was performed to compare the canopy cover obtained using these image tools with the measured dry forage mass. Quadratic regressions were developed using 80% of the data. Validation of the predicted and measured forage mass was conducted using the remaining 20% of the data. Both tools showed strong predictive potential, with the CCIA being relatively simpler to operate and exhibiting slightly superior performance (r² = 0.78; RMSE = 362 lb DM ac⁻¹) compared with Canopeo (r² = 0.72; RMSE = 446 lb DM ac⁻¹). Our results indicated that canopy cover relative to forage mass showed greater variability at more mature phenological stages, plausibly attributed to stem elongation rather than leaf mass accumulation. These findings suggest that both tools are suitable for use during the vegetative stage, when grazing typically occurs, but may be less accurate at advanced maturity stages. Nondestructive image-based approaches offer a practical, time-saving alternative to traditional methods and hold promise for supporting producers and scientists in making timely grazing decisions.

Rotational bale grazing (RBG), the strategic feeding of round hay bales directly on pasture with controlled access, offers an alternative to continuous winter hay feeding in a single paddock. This study evaluated RBG's potential to redistribute nutrients by increasing soil concentrations in field areas with lower phosphorus (P) and potassium (K) concentrations while mitigating excess concentrations in other areas. Soil nutrient concentrations were measured over 2 years before and after RBG implementation. Changes in Mehlich 1-P, Mehlich 1-K, water-soluble P, nitrate-nitrogen (NO₃-N), and pH values were compared across three treatments: (a) RBG bale (soil grids where hay bales were placed in the RBG system), (b) RBG no-bale (soil grids where no-bales were placed in the RBG system), and (c) continuous (soil under continuous winter hay feeding for >2 decades). The RBG bale treatment added Mehlich 1-P to the soil, but not in sufficient quantities to significantly increase concentrations compared with the RBG no-bale treatment. In contrast, Mehlich 1-K values increased substantially in the RBG bale treatment areas. Each hay bale applied ∼17.86 lb of K, far exceeding the amount needed to raise soil test K concentrations by 1 ppm. Water-soluble P remained stable in the RBG bale treatment areas but decreased in the RBG no-bale treatment areas. Bale placement had no significant effect on NO₃-N or pH values. These findings demonstrate RBG's potential to improve soil fertility in nutrient-deficient pasture areas, particularly through notable increases in Mehlich 1-K values.

Seed moisture content (SMC) is the most reliable indicator of seed maturity and the optimal harvest timing in grass seed crops. Current SMC testing methodologies used in grass seed crops are slow or inaccurate, making it difficult to make timely harvest decisions. Harvesting too early can result in low seed weight and poor seed germination. Delaying harvest past the point of physiological maturity reduces seed yield by increasing losses due to shattering. Our objective was to validate the feasibility of using portable near-infrared reflectance spectroscopy (NIRS) as a field-based alternative to the oven method for determining SMC in cool-season grass seed crops. Eight cool-season grass species were used in field testing of the portable NIRS sensor over eight harvest seasons. Daily testing of SMC began when grass seed crops were at Biologische Bundesanstalt, Bundessortenamt and Chemische Industrie (BBCH) growth stage 69 and continued until windrowing. Seed samples were collected from each crop by cutting ∼40 inflorescences, then stripping the seeds into airtight containers until ready for estimation of SMC with a portable NIRS sensor, using SMC measurement by laboratory air-oven (130°C) as the reference method. The SMC estimates made by the portable NIRS sensor were predictive of the actual SMC determined by the oven reference method across all eight grass species. These SMC predictions by the sensor closely followed the seasonal loss of SMC as the seed matured. Spring agronomic practices (mowing, plant growth regulators, foliar fungicides, and nitrogen fertilization) did not influence NIRS predictions of SMC compared with untreated controls. The portable NIRS sensor is a promising tool for determining harvest timing in grass seed crops by using predicted SMC values.

Sub-Saharan Africa faces a severe and growing ruminant feed deficit, constraining livestock productivity and the development of sustainable, climate-resilient food systems. This article quantifies the deficit and assesses the role of improved cultivated forages in closing it across 10 countries: South Sudan, Sudan, Somalia, Malawi, Zambia, Zimbabwe, Mozambique, Mali, Senegal, and Nigeria. The analysis estimates that addressing the forage gap over a 10-year horizon would require more than 1.2 million hectares of cultivated forage, the engagement of over 1.1 million farmers, and up to 100,000 metric tons of seed. This expansion represents a major economic opportunity, with a potential forage seed market value of US$247–424 million and forage crop value of US$3.4–6.2 billion, depending on the adoption scenario. Despite growing policy recognition of feed shortages in the studied countries, systemic barriers—including weak and import-dependent seed systems, limited private-sector investment, land competition, and inadequate extension services—continue to restrict forage adoption. Closing the feed gap will require integrated technical and institutional measures: strengthening local seed production, harmonizing regional seed regulations, incentivizing private-sector engagement, improving farmer training, and embedding forage development into livestock strategies. With coordinated investments, improved forages can significantly increase livestock productivity, rural incomes, and climate resilience across sub-Saharan Africa.

Poa annua L. is a widespread and persistent weed in managed turfgrass systems, exhibiting both annual and short-lived perennial growth habits. Effective management requires an integrated approach, with chemical herbicides remaining a primary tool. This review outlines the current landscape of chemical control strategies, including pre-emergence and post-emergence herbicide options, plant growth regulators, and emerging chemistries. Herbicide resistance in Poa annua continues to pose a significant challenge, with confirmed cases spanning multiple modes of action. Consequently, sustainable management depends on rotating herbicide classes, using mixtures and sequences of treatments, and integrating nonchemical tactics. Continued research into novel herbicide modes of action, application technologies, and integrated weed management approaches will be critical for maintaining long-term control of Poa annua across diverse turfgrass systems.