Agrosystems, Geosciences & Environment最新文献

Cowpea (Vigna unguiculata (L.) Walp.), is an important crop for addressing food security in Africa, especially Ghana. However, its production is limited by soil nutrient deficiencies, particularly nitrogen (N). This study aimed to assess the impact of N fertilizer application and inoculation on the growth and yield of cowpea. A factorial experiment was conducted with two inoculant strains (WB74and BR 3262) and four N fertilizer levels (0, 15, 30, and 45 kg N/ha) laid out in a randomized complete block design with four replications. Plant height, branching, leaf number, yield components, N fixation, and N derived from the atmosphere were measured. At 25 and 35 days after planting (DAP), the 45 kg N/ha treatment produced the tallest plants, which was significantly higher than those from other treatments. Both inoculant strains improved growth compared to the control. The 45 kg N/ha treatment had the most branches, while the 30 kg N/ha treatment had the most nodules per plant. At 40 DAP, the WB74 had the most effective nodules. The 45 kg N/ha treatment produced the highest grain yield, and the BR 3262 strain outperformed the control and WB74. N fixation and N derived from the atmosphere were highest with the 45 kg N/ha treatment, and the BR 3262 inoculant had greater N fixation than the other treatments. For optimal cowpea growth, N fixation, and yield, a combination of N fertilizer application and inoculation should not be overlooked.

Zinc malnutrition ranks fifth in terms of the leading cause of disease in developing countries. Agronomic biofortification is an effective way to increase micronutrient concentrations in grain crops. A greenhouse experiment was conducted to investigate the effectiveness of various Zn sources (organic and inorganic) with and without organic C-based co-additives (AVAIL and humic acid) on the biofortification of wheat (Triticum aestivum L.) with Zn in a mildly calcareous soil. Specifically, the objective is to determine the distribution (stems/leaves, whole grain, bran, and flour) and bioavailability of Zn in different plant parts. The results of this study indicated that application of inorganic Zn in various forms significantly increased grain yield from 26% to 41% compared with the fertilized control. Similarly, grain Zn concentration in wheat increased by 58% when applied as ZnO and by 30% when Zn is applied as ZnSO₄. Flour phytate (PA) to Zn ratio with the addition of Zn as ZnSO₄ and ZnO with and without co-additives to the soil was relatively lower (<8) than with the addition of granular Zn (>10) treatments (MAP-ZnSO₄ and MAP-ZnO), with and without co-additives, and low PA:Zn ratio ensures increased Zn bioavailability. Between the two, less soluble ZnO showed more promising results (greater Zn concentration in whole grain, bran, and aboveground biomass) compared to soluble ZnSO₄. Co-additives did not improve soil Zn extractability or Zn uptake by wheat. We concluded that Zn application resulted in successful biofortification of wheat grain with Zn while simultaneously increasing yield. This is a greenhouse study under controlled environmental conditions, and therefore, we recommend further field research in multiple years and locations to confirm or challenge these results.

Divots are pieces of the turfgrass sward removed when golf clubs strike playing surfaces with impact energy that exceeds turfgrass shear strength. Divot resistance and recovery are factors affecting turfgrass species and cultivar selection for golf courses. Research was conducted in Knoxville, TN, during 2022 and 2023, evaluating divot resistance and recovery of two hybrid bermudagrasses [C. dactylon (L.) Pers. × C. transvaalensis Burtt-Davy, cv. Tifway (TIF) and cv. Latitude 36 (L36)] and one creeping bentgrass (Agrostis stolonifera L., cv. L93-XD). A third hybrid bermudagrass (Tahoma 31 [T31]) was included in 2023. A pendulum apparatus was used to create 100 divots on each surface in May each year. Divot resistance was indirectly quantified by measuring the volume of sand used to fill each divot scar. Divot recovery was evaluated via visual assessments of turfgrass cover within the divot scar over time. Divot recovery data were fit to a nonlinear regression model to determine days required to reach 25%, 50%, 75%, and 95% recovery (i.e., Days₂₅, Days₅₀, Days_75, and Days₉₅). Divot resistance for TIF, L36, and T31 was greater than L93-XD each year. Divot recovery was faster on hybrid bermudagrass in 2022 (Days₉₅ = 28–44) than 2023 (Days₉₅ = 40–77 days); the opposite response was observed on creeping bentgrass with fewer days required for recovery in 2023 compared to 2022. Among hybrid bermudagrasses, Days₉₅ values were lowest for T31 and highest for TIF, with L36 ranking intermediate. However, T31 data were limited to a single year.

Soil surfactants are applied to recreational turfgrass areas like golf course putting greens to help improve water infiltration, distribution, and uniformity. Most commercially available surfactant labels recommend immediate post-application irrigation (PAI) to maximize product efficacy. However, many turfgrass managers may forgo PAI due to potential concerns of excess surface wetness, reduced surface firmness, or time constraints with golf play. A field study was conducted in 2024 to evaluate the effect of immediate PAI for two surfactant chemistries ([polyoxyalkylene polymer [PP] [8.0 L ha⁻¹] and a blend of alkoxylated ethylene oxide-propylene oxide adducts/nonionic polyols [AEPA] [6.4 L ha⁻¹]) on a sand-based creeping bentgrass (Agrostis stolonifera L.) research green in West Lafayette, IN. Surfactants were initially applied on May 30, 2024 and reapplied every 14 days for a total of nine applications and received either immediate PAI with 0.5 cm water or scheduled nightly irrigation approximately 18 h after application across the study area. Visual turfgrass quality, percentage of turfgrass stress, soil volumetric water content (VWC), and water droplet penetration time (WDPT) were measured. Both surfactants improved seasonal quality and reduced stress/wilt with or without immediate PAI. Compared to the non-treated control, the surfactants increased VWC and reduced WDPT in the upper 0–1 cm in early September. Immediate PAI increased average VWC and reduced WDPT in late summer compared to the non-treated control. This 1-year field study reinforces the value of immediate PAI to maximize surfactant efficacy and turfgrass health, especially during late-summer stress.

Soil compaction commonly impacts productivity in Australian cotton production systems. A field experiment conducted during the 2019–2020 season showed that compaction decreased lint yield by 27%. The objective of this study is to evaluate the legacy effect of soil compaction on subsequent crop yields (wheat [Triticum aestivum L.] in 2020 and 2022 and cotton [Gossypium hirsutum L.] in 2021–2022). Wheat and cotton yields, cotton biomass, Verticillium wilt incidence in cotton, soil water, and soil strength were assessed. There was no legacy effect of soil compaction on the wheat grain yields in the 2020 and 2022 seasons. The lack of difference in wheat yields is the result of sufficient rainfall recharging the soil profile during the growing season to overcome compaction limitations of deeper soil water extraction. Similarly, there was no legacy effect of soil compaction on cotton lint yield or fiber quality in the 2021–2022 crop. We found no difference in soil strength (penetrometer resistance) or soil water use by cotton during the 2021–2022 season. These results suggest, indirectly, that cotton root systems were not constrained from extracting water from lower depths of the soil. Verticillium wilt was absent in the compacted plots, and its incidence reached 15.3% in the uncompacted plots during the 2021–2022 season. The legacy effect of soil compaction may not impact subsequent crop yields under the right climatic conditions. However, a study conducted during dry years could offer further insights into its long-term impact. Future research should be expanded to explore the relationship between disease incidence and soil compaction.

Much of the research for tarping and soil health has taken place in the northeastern United States, and minimal research has applied early season tarping in a drier, sunnier climate such as the US Midwest. This study in Brookings, SD, evaluated soil health impact from early season (April through May) solarization and occultation at different durations (6, 4, and 2 weeks) used for weed control in onion (Allium cepa) production during 2023 and 2024. Solarization was conducted using greenhouse plastic, while occultation was evaluated using both white side up and black side up silage tarps. A randomized complete block design with four blocks and ten treatment plots per block, including an untarped, tilled control, was established. Immediately following tarp removal, clear and untarped control plots were tilled to remove high weed pressure, and all planting beds were harrowed within each plot where onions were planted. Soil response variables included inorganic nitrogen (N), soil respiration, active carbon (POXC), organic N, temperature, and moisture. Daily temperatures were up to 6°C higher in solarized plots compared to occultation plots during tarping. Occultation treatments showed trends of lower moisture during tarping and higher moisture during the growing season when compared to control plots. No differences were seen among tarp treatments for N, soil respiration, or POXC. While early season soil tarping used in the US Midwest can manipulate temperature, our research showed no significant impacts on other soil health indicators.

Achieving greater productivity and ecological sustainability of agricultural soils requires moving beyond conventional management practices. No-till (NT) enhances soil health while presenting weed management and nutrient stratification challenges. Occasional tillage (OT) carried out once every 6 years presents a chance for alleviating these problems without altering soil quality and research in this field continues evolving. This study evaluated the effect of a change from NT to OT on soil health while relating their performance to native sods consisting of native prairie vegetation. The long-term tillage study was established in 1970 as winter wheat (Triticum aestivum L.)–fallow. Original treatments included continuous NT, stubble mulch (SM), moldboard plow (MP), and native sod. In 2010–2011, the plots associated with NT, SM, and MP were each split into two and assigned either NT or OT. Here, we used the original NT plots (comprising of OT and NT) and native sods. Soil samples were collected from 0 to 15 cm. Soil organic carbon, active carbon, respiration, and protein were not substantially different between NT and OT (p ≥ 0.05). The same soil health indicators with OT and NT were substantially low compared with native sod (p < 0.00001) and were of the order native sod > NT = OT. Depending on the indicator considered, soil health differences between tillage practices and native sod were variable with the difference ranging from 28 % to 182 %. For over 14 years encompassing two OT events, soil health indicators remain unaltered relative to NT, offering a potential solution to weed and pest management challenges associated with continuous NT.

There has been a rapid increase in research to understand the genetic and agroclimatic interactions of hemp (Cannabis sativa L.) relative to its economic viability. Initial field trials at New Mexico State University were conducted in 2021 and 2022 at three sites across the state for high-cannabidiol (CBD), grain, and fiber hemp types. The goal of this work was preliminary evaluation of factors, such as variety choice and production conditions (specifically, water stress and organic management), to highlight topics that should be studied in full variety trials. Even with the limited scope, two important lessons from the studies are expected to be valuable for the developing industry: (a) the majority of available, compliant industrial (grain/fiber) varieties show severely shortened vegetative phases and early reproductive responses at low latitudes; and (b) high-CBD varieties perform inconsistently in outdoor production, rarely producing flower biomass yields and total CBD content necessary for economic viability. Future work is needed in the southwestern United States to find grain/fiber varieties with genetics suitable to the latitude and to reduce the costs of indoor production of CBD varieties.

Sorghum (Sorghum bicolor L. Moench) is an important and genetically variable food crop. In Hirna, eastern Ethiopia, 49 sorghum genotypes were evaluated for genetic diversity, heritability, genetic advance, and correlations throughout the main rainy seasons of 2017 and 2018. The experiment was arranged in a lattice square design with three replications. Information on traits relating to yield and phenology was collected. The analysis of variance revealed significant differences (p < 0.01) between the sorghum genotypes for each parameter in both experimental years. The phenotypic and genotypic variants for the cropping years 2017 and 2018 were 5.07%–26.36% and 7.10%–27.35%, respectively, and 6.70%–21.09% and 4.16%–21.30%. The highest estimates of heritability were linked to high genetic advance over mean for days of 50% blooming, leaf number, panicle length, 1000-seed weight, severity, and area under the disease progress curve in the 2 years. Over the course of the two trial years, correlation analysis showed a varied relationship between the qualities. Leaf width, leaf number, leaf length, leaf area, panicle length, panicle weight, and panicle width have shown a positive and significant correlation with grain yield. However, it exhibited strong and negative relationships with anthracnose disease parameters at the genotypic and phenotypic levels across the two growing seasons. The current experiment revealed high levels of genotypic and phenotypic diversity in Ethiopian sorghum genotypes, which raised the prospect of taking the variety into account for next development initiatives. Furthermore, the high heritability together with the high genetic advance observed in the studied characters indicated that selection based on these traits could be rewarding.

Industrial hemp (Cannabis sativa L.) has garnered increasing attention in the United States for its environmental and economic potential, yet its effects on mineral soil health remain largely unexplored. This study assessed the impact of hemp cultivation on soil quality by examining different hemp varieties and nitrogen (N) fertilization rates across three distinct subtropical agroecosystems in Florida. Over 2 years, field experiments were conducted at three University of Florida/Institute of Food and Agricultural Sciences research centers—West Florida Research and Education Center (Dothan fine sandy loam, pH 6.25), Plant Science Research and Education Unit (Arredondo sand, pH 6.25), and Tropical Research and Education Center (Krome gravelly loam, pH 8.4)—using a randomized block design. Three hemp varieties (IH-Williams, Wife, and Maverick) were cultivated under varying N application rates to evaluate their effects on soil organic matter (OM), nutrient levels (total and available N, and total phosphorus and potassium), and potential environmental benefits, such as reducing soil nitrate-N (NO₃⁻-N) losses in agricultural systems. Results indicated that hemp cultivation, particularly with high-cannabidiol varieties Wife and Maverick grown for flower production, significantly (p < 0.05) increased soil OM and influenced soil N dynamics. All hemp varieties significantly (p < 0.05) reduced NO₃⁻-N concentrations, while N fertilization had varying effects on total N and ammonium-N. Such findings will contribute to developing best management practices for optimizing nutrient applications and maximizing hemp's potential in improving soil health and promoting environmental sustainability across Florida's agricultural landscapes.