Agronomy Journal最新文献

This study investigated the impact of climate variability on pigweed (Amaranthus spp.) management in processing tomato (Solanum lycopersicum) fields across northern Israel, which span a climate gradient from semiarid to Mediterranean conditions. Conducted over two consecutive growing seasons (2020–2021), the research aimed to optimize weed management recommendations on a regional scale. The main objectives were to assess treatment timing and intensity and evaluate the efficacy of integrated weed management (IWM) in reducing reliance on herbicides. In 2020, standard chemical treatments—a tank-mix application of metribuzin (175 g a.i. ha⁻¹) and rimsulfuron (25 g a.i. ha⁻¹)—were applied in six field experiments based on cumulative growing degree days (GDD) to account for climate variability among sites. An infestation index was developed to represent the initial state of the fields and the magnitude of the change in infestation. In 2021, IWM was introduced, combining finger weeder cultivation with herbicide treatments at three sites. Results from the first season showed that in early-plantings, a single herbicide application at 150 GDD was as effective as dual applications at 150 and 300 GDD. However, in late plantings, a single application at 300 GDD was ineffective. In the second season, all treatments effectively reduced Amaranthus infestation, with IWM performing comparably to herbicide alone. Importantly, IWM demonstrated the potential to control herbicide-resistant biotypes while minimizing chemical use, making it an environmentally sustainable option. This study underscores the importance of optimized application timing for minimizing unnecessary chemical treatments, offering valuable insights for growers facing future climate challenges.

Controlling weed populations and improving soil health while producing high yields are top priorities of organic crop farmers yet are difficult to achieve simultaneously due to the importance of cultivation for weed control. This study examined whether less frequent cultivation for weed control and the application of carbon-rich soil fertility amendments would enable progress toward those goals during the 3-year transition period to organic production. Standard weed control with cultivation was compared to high-frequency cultivation combined with delayed planting. The standard approach produced 7% higher crop yield over the course of a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–small grain rotation, likely due in part to earlier corn and soybean planting. In-field weed counts and weed seedbank germination showed weed populations tended to be lower in the high-frequency cultivation treatment, although patterns were crop specific. Weed populations increased over the 3 years in all treatments, suggesting that additional weed control tactics may have been beneficial. Carbon-rich poultry manure had no significant effects on weed populations, soil health, or crop yield compared to an N-rich organic fertilizer. However, crop yields were positively related to soil health indicators, specifically greater soil total carbon and nitrogen and permanganate oxidizable carbon. The standard weed control approach was advantageous during the organic transition period, but the observed increase in weed populations might become problematic in future years of organic production.

Conservation cropping systems provide many ecosystem service benefits, but must improve or maintain profitability to be economically viable. This study was conducted to determine the sustainability of conservation tillage in continuous cotton (Gossypium hirsutum L.). The effects of subsoil tillage, strip-tillage, no-seedbed-tillage, and cover crops on irrigation costs and overall profitability in comparison with a conventionally tilled control were investigated. The study was located near Stoneville, MS, on a Dubbs silt loam (fine-silty, mixed, active, thermic Typic Hapludalf) and a Bosket very fine sandy loam (fine-loamy, mixed, active, thermic Mollic Hapludalf). The lowest costs per hectare were realized when the no-seedbed-tillage with winter fallow treatment was used. Using a cover crop reduced irrigation expenses by $18.29 ha⁻¹ compared to the conventionally tilled control (p > F = 4.1 × 10⁻⁵). However, revenues were reduced by $279 ha⁻¹ where cover crops were sown (p > F = 0.043), and returns were reduced by $497 ha⁻¹ (p > F = 0.007). The strip-tillage and no-seedbed-tillage systems with winter fallow reduced overall variability of production when compared to the conventional control and treatments with a cover crop. Adopting the no-seedbed-tillage with winter fallow system provided the best returns by reducing expenses and lowering variability.

The lack of soil fertility is one of the main constraints for oil palm production. In Benin, scientific research has been conducted to address this problem. This article summarizes the scientific work conducted in Benin so far on soil fertility management in oil palm grove. To produce this review, we used peer-reviewed articles and references. It has enabled us to categorize the various works on soil fertility in Benin palm plantations into three categories, which include works on the management of organic matter, works on the association of oil palm with annual food crops, and works on the management of mineral fertilization. From all these studies, apart from climatic factors, the major constraint affecting oil palm production is potassium (K) deficiency. But boron (B) is also mentioned in the scientific literature as a parameter requiring particular attention, whose deficiency leads, in addition to K, to enormous production losses. It would therefore be advisable to direct future research toward alternatives that take into account climatic variability and the mineral nutrition of oil palm in K and magnesium (Mg), while ensuring good management of soil organic matter to ensure the sustainability of oil palm-based production systems.

Italy is the most important European producer of organic (ORG) durum wheat [Triticum turgidum spp. durum (Desf.) Husn.]. Growth and yield of durum wheat are affected by weather conditions and by management systems (MS). The objective of this research was to determine the long-term impact of two different MS (ORG and conventional [CON]) and their interactions with weather conditions on durum wheat yields. The study was part of a long-term experiment in Pisa, Italy, comparing crop performance in a 5-year rainfed rotation (i.e., sugar beet [Beta vulgaris L. var. saccharifera] or maize [Zea mays L.] followed by common wheat [T. aestivum L. subsp. aestivum emend. Thell.], sunflower [Helianthus annuus L.], faba bean [Vicia faba L. var. minor], and durum wheat) over 15 years under ORG and CON MS. Durum wheat yields were 37% lower under ORG compared to CON on average, though similar yields were produced across the two systems during one of the 5-year cycles. There was a significant interaction between MS and climatic conditions for yield and yield components. A lower number of spikes per m² was observed in ORG wheat compared to CON, thus spotlighting on likely different soil N availability in the two MS at the double ridge stage. ORG management resulted in weed biomass increases over time, with 400% higher weed biomass under ORG by the end of the research period. The high interannual variability across both MS confirms that multi-year studies are needed to demonstrate the relative productivity of ORG versus CON MS.

Implementing an integrated system of reduced tillage and cover cropping holds promising potential for enhancing cotton (Gossypium hirsutum L.) production in the southeast, where soils are eroded and low in organic matter. A 4-year field study was conducted on a Leeper silty clay loam at the Plant Science Center at Mississippi State University to investigate the combined effects of no-till (NT) and conventional tillage (CT), with applied broiler litter (BL) and inorganic N fertilizer, in the presence of winter cover crops (WCCs) and absence of cover crops on cotton growth and yield. With WCC residues, NT had the greatest soil moisture in the drier year of 2022. Total aboveground biomass of WCC and nitrogen (N) accumulation were 72% and 60% greater in the 2019/2020 growing season than in the 2020/2021 and 2021/2022, and they were 24% and 22% greater with CT than NT. However, cotton dry matter (DM) was 22% greater with NT than CT. With WCC residues, cotton DM, N uptake, and leaf area index were greater by 25%, 21%, and 64%, respectively. Regardless of tillage and cropping systems, BL in the presence of WCC residues increased cotton lint yield by 67%, especially in years with less rainfall during cotton peak blooming and boll formation. This study revealed that the integration of NT with BL and inorganic N fertilizer in the presence of a cover crop can have a positive effect on cotton production. Implementing these practices could enhance long-term sustainable cotton cultivation in southeastern United States agroecosystems.

Intercropping faba bean and wheat in semi-arid areas is a promising agricultural practice that has the potential to enhance crop yields and economic benefits. Farmers commonly use this practice in semi-arid regions of Ethiopia. Yet there is limited information on grain yield and economic advantages of faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) intercropping systems. This study aimed to determine the effects of faba bean intercrops with wheat varieties at different seeding rates on grain yield, economic revenue, and land-use efficiency. The study was conducted in 2013 and 2014 at Mekelle Agricultural Research Centre, northern Ethiopia (Latitude 13° 30′ 00ʺ N, Longitude 39° 28′ 11ʺ E, and elevation 1970 m). The study considered three wheat varieties (Shehan, HAR 2501, and Mekelle 01) at three seeding rates (25%, 50%, and 75%) of the recommended sole wheat seeding rate of 150 kg ha⁻¹ intercropped with faba bean at 250,000 plants ha⁻¹. Sole cropping of each wheat variety and faba bean at the recommended seeding rates served as controls. Faba bean intercropped with the wheat HAR 2501 variety at a 75% seeding rate increased the total grain yield, economic revenue, and land equivalent ratio (LER) by 39%, 17%, and 50%, respectively, over the sole faba bean. The study suggests that intercropping faba bean and wheat can be a sustainable farming practice to enhance crop grain yield and land-use productivity in semi-arid areas.

Soil erosion significantly affects within-field soil properties, crop productivity, weed emergence patterns, and weed growth. Spatial variability in weed densities, emergence timing, weed seed production, seed viability, herbicide bioavailability, and other factors complicate weed management strategies in eroded landscapes. Reversing soil erosion by replacing translocated topsoil (soil-landscape rehabilitation) is one method to improve crop productivity of severely eroded land, but bulk soil movement changes soil properties and weed seedbanks that influence weed spatial distribution patterns, emergence, and growth. We evaluated weed community responses to soil movement within a hilly landform. Soil-landscape rehabilitation was performed by moving 15–20 cm of accumulated topsoil from the lower slope and adding it to the upper slope positions (areas of net soil loss by erosion). Adjacent plots were left in their eroded condition. Weed density and species richness were monitored for 4 years. Annual grasses dominated the weed community in the upper slope, and weed abundance was highest in the most eroded landscape positions. Soil addition improved soil characteristics for crop growth but did not increase weed densities. The density of weeds was lower where soil was removed in the first 2 years after soil movement, likely through removal of weed seeds with soil. Within 3 years of soil movement, weed abundance and species richness were the same or lower in areas of soil removal and no soil removal. In these experiments, movement of soil (and entrained weed seeds) within an eroded landform to improve productivity did not exacerbate weed issues.

Soil test-based fertilizer recommendations traditionally serve to predict average nutrient needs across fields, but their effectiveness for precision agriculture remains uncertain. Our objectives were to evaluate whether soil phosphorus (P) concentrations predicted corn (Zea mays,r L.) yield response to P at the sub-field level, and to determine if soil test critical levels varied within field boundaries. We conducted research over seven growing seasons at two Kentucky sites collecting spatially dense yield response data from over 150 paired plots per field. Mehlich 3 extractable phosphorus (M3P) soil ranged from 0.8 to 63 mg kg⁻¹, with 96% of sample points falling below the University of Kentucky's fertilizer cutoff of 30 mg kg⁻¹ M3P for corn. Each plot (10⁻² ha) received 0 or 29.5 kg ha⁻¹ P. While M3P effectively predicted average field-level response, with yield increases in five of seven site-years, it failed to predict subfield responses, where only 51% of plots showed positive yield response to P application. Linear plateau models revealed that conventional statistical treatments of soil test correlation data mask important subfield variability. The poor relationship between soil test P and yield response at the subfield scale suggests that variable rate P management requires incorporating additional factors beyond soil P concentration or moving away from such deterministic models toward probabilistic models. Our findings demonstrate that while current soil test recommendations provide accurate field-scale guidance, they lack the precision required for variable rate application.

Soybean [Glycine max (L.) Merr.] provides plant-based protein for global food production and is extensively bred to create cultivars with greater productivity in distinct environments through multi-environment trials (MET). The application of MET assumes that trial locations provide representative environmental conditions that cultivars are likely to encounter when grown by farmers. A retrospective analysis of MET data spanning 63 locations between 1989 and 2019 was conducted to identify mega-environments (ME) for soybean seed yield in the primary production areas of North America. ME were identified using data from phenotypic values, geographic, soil, and meteorological records at the trial locations. Results indicate that yield variation was mostly explained by location and location by year interaction. The phenotypic variation due to genotype by location interaction effects was greater than genotype by year interaction effects. The static portion of the genotype by environment interaction variance represented 26.30% of its total variation. The observed locations sampled from the target population of environments can be divided into two or three ME, thereby suggesting that improvements in the response to selection can be achieved when selecting directly within clusters (i.e., regions and ME) versus selecting across all locations. In addition, we published the R package SoyURT that contains the datasets used in this work.