Successive Crops Research Articles

The allelopathic effect of para-hydroxybenzoic acid on the gene expression of photosynthesis and respiration in Solanum lycopersicum

As an important economically and nutritionally valuable vegetable, tomato has been planted everywhere worldwide, which has resulted in a succession cropping obstacle due to the shortage of farmland. The effects of plant allelopathy, one of the major obstacles to succession cropping, has not been fully defined or explored, especially on plant gene expression profile changes. In this study, the high-throughput sequencing technology was used to analysis the gene expression in tomato leaves treated with the Para-hydroxybenzoic acid (PHBA), an important allelochemical, that was found to have the highest content in the soil of succession cropped tomatoes. We found the expression of genes related to respiration, photosynthesis, starch and sucrose metabolism, amino acid metabolism, pyrimidine metabolism, and ROS metabolism was changed in response to PHBA treatment. Our study on the allelopathic effects of PHBA on photosynthesis and respiration in Solanum lycopersicum has provided a solid evidence for the negative effect of allelochemical on the transcriptomic profiles needed for normal physiological activities of succession cropped tomato, thus will be beneficial for improving our knowledge of the mechanism of plant allelopathy.

Biochar Effects Coastal Saline Soil and Improves Crop Yields in a Maize-Barley Rotation System in the Tidal Flat Reclamation Zone, China

The summer maize-winter barley (or wheat) rotation system is a conventional farming method in coastal areas of east China. However, researchers have paid little attention to the increasing soil degradation after successive crop rotation in coastal saline agriculture. In the current study, a two-year field experiment was conducted to investigate the changes in soil physio-chemical properties and crop grain yields under the maize-barley rotation system. Wheat straw derived biochar (BC) was applied to topsoil (0~20 cm) at four different rates (0, 7.5, 15 and 30 Mg ha−1) before summer maize cultivation, and no biochar was added in the cultivation of the winter barley. Bulk density (BD), water holding capacity (WHC), water stable aggregate (WSA), soil electrical conductivity (EC), pH (1:5 water w/v) and soil organic carbon (SOC), at the harvesting time of maize and barley, were analyzed. The application of biochar increased WHC and macro-aggregate (>2 mm) content after barley harvest. Soil EC was mainly affected by the rain during maize cultivation and increased only slightly under BC treatments. However, no difference in EC was found among all treatments after barley harvest. The application of BC at 30 Mg ha−1 increased the maize yield by 66% but produced no difference in the barley yield. We concluded that biochar could be an effective option to mitigate soil degradation and improve crop productivity in coastal saline agriculture.

Effect of inoculum spraying on rice (Oryza sativa) residue decomposition kinetics

Rice (Oryza sativa L.) residues on Indian farms have remained a major challenge due to its voluminous and unmanageable quantity and short window for sowing successive crops. A study was carried out at research farm of the ICAR-Indian Agricultural Research Institute, New Delhi during 2019–21, to develop a microbial inoculum spraying system for efficient decomposition of rice residues. The study involved the evaluation of flood nozzles at different operational parameters like operating pressure (1.5, 2.5 and 3.5 kg/cm2), nozzle heights (50, 60 and 70 cm) and forward speeds (2.5 and 3 km/h). The inoculum spray was characterized in terms of Volume Median Diameter (VMD), Number Median Diameter (NMD) and Droplet Density (DD). The decomposition kinetics was studied in terms of total organic carbon, total nitrogen, phosphorus, potassium and N-acetyl glucosamine observed at an interval of 10 days and 20 days after inoculums application. VMD and NMD were found in the range of 347–243 μm and 77.67–87.8 μm respectively, whereas droplet density ranging from 252.5–403.9 droplets/cm2 to spray microbial inoculum using flood nozzle. The C:N ratio of rice residue was reduced by 19.96% and 36.77% respectively after 10 and 20 days of rice residue decomposition compared to control. Carbon content reduced from 47.98–41.24% and total nitrogen content increased from 0.532–0.728 % after 20 days of decomposition. The N-acetyl glucosamine content of rice residue increased from 0.77–3.53 mg/g after 20 days indicating that target-oriented microbial inoculum spraying accelerates the decomposition kinetics of rice residues.

Intelligent Control of Irrigation Systems Using Fuzzy Logic Controller

In this paper, we explain the design and implementation of an intelligent irrigation control system based on fuzzy logic for the automatic control of water pumps used in farms and greenhouses. This system enables its user to save water and electricity and prevent over-watering and under-watering of the crop by taking into account the climatic parameters and soil moisture. The irrigation system works without human intervention. The climate sensors are packaged using electronic circuits, and the whole is interfaced with an Arduino and a Simulink model. These sensors provide information that is used by the Simulink model to control the water pump speed; the speed of the water pump is controlled to increase or decrease the amount of water that needs to be pushed by the pump. The Simulink model contains the fuzzy control logic that manages the data read by the Arduino through sensors and sends the command to change the pump speed to the Arduino by considering all the sensor data. The need for human intervention is eliminated by using this system and a more successful crop is produced by supplying the right amount of water to the crop when it is needed. The water supply is stopped when a sufficient amount of moisture is present in the soil and it is started as soon as the soil moisture levels drops below certain levels, depending upon the environmental factors.

Mechanical and Biological Soil Decompaction for No-Tillage Maize Production

Soil structural quality in areas under a no-tillage system is altered after successive crops, where compaction is a recurrent problem. The objective of this study was to evaluate the effect of different forms of soil decompaction on maize grain production. A randomized split-plot block design with four replications was used, in a 5 × 3 × 2 factorial arrangement, consisting of five forms of mechanical soil decompaction: ripping to a depth of 0.3 m, ripping to a depth of 0.5 m, subsoiling to a depth of 0.3 m, and subsoiling to a depth of 0.5 m, and no-tillage; three crop seasons: 2014/2015, 2015/2016, and 2016/2017; and two cover crops: sunn hemp and pearl millet. The soil resistance to root penetration (RP, 0.0–0.40 m), density (0.0–0.40 m), moisture (0.0–0.40 m), fresh (FB), and dry (DB) above-ground biomass of cover crops, and maize yield were evaluated. The subsoiling to a depth of 0.3 or 0.5 m results in higher production of sunn hemp biomass but has no effect on millet. Mechanical and biological soil decompaction improved maize grain yield throughout the seasons by at least 28% above the average yield in the study area region. The RP of up to 3.3 MPa did not negatively affect cover crop biomass production and maize grain. The association between the mechanical and biological decompaction method using cover crops provided greater resilience to the preparation carried out up to three years after the application of the treatments, resulting in greater corn grain productivity.

Wheat Curl Mite: A New Source of the Eriophyoid Mite in Wheat Fields Identified

Wheat curl mites (WCMs; Aceria tosichella) are an important global pest of cultivated wheat. Their feeding activities on epidermal cells of wheat leaves result in characteristic leaf curl symptoms that prevent the unfurling of affected leaves and impair the proper emergence of heads from the boot stage. The most significant economic impact of WCM infestation, however, is their ability to vector and transmit four important viruses of wheat, specifically, wheat streak mosaic virus, Triticum mosaic virus, High Plains wheat mosaic emaravirus, and brome streak mosaic virus. Being wingless, WCMs are almost completely dependent on air currents for their dispersal. In addition, because of their obligate lifestyle, wheat field infestations are thought to originate from sources such as volunteer wheat. Corn and other cultivated and noncultivated Poaceae hosts are also known to act as green bridges between successive wheat crops. Consequently, management practices mostly target these off-season host plants but also the use of resistant varieties and other cultural control methods. Here we report the discovery of seed-borne WCM eggs, a previously unknown method of their dispersal, as a possible source of new infestations in wheat fields. This discovery expands our understanding of the biology of WCMs, with potential implications for the development of more holistic and effective management strategies for this economic pest and virus vector. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

Impact of edaphoclimatic conditions and crop season on olive oil's fatty acids

AbstractThe olive tree (Olea europaea L.) fruit oil attracts widespread interest because of its high content of monounsaturated fatty acids. However, a neglected area in the field is the edaphoclimatic factors impact, which is poorly understood. Bearing this in mind, the purpose of this investigation was to evaluate the impact of the edaphoclimatic conditions on the fatty acids’ composition. Therefore, we have investigated the fatty acids methyl ester (FAME) profile in 38 monovarietal Moroccan ‘Picholine Marocaine’ extra‐virgin olive oils (EVOOs) from two successive crop years (2018–2019 and 2019–2020). Significant differences were detected in olive oils from distinct geographical origins with about 10 and 4% of the difference in oleic and palmitic acid amounts in both seasons; however, linoleic acid showed 5 and 8% in 2018–2019 and 2019–2020 oils, respectively. Furthermore, regions of high altitude and low temperature resulted in olive oils rich in oleic acid and monounsaturated fatty acids (MUFAs). This study also revealed the negative impact of rainfall, sand percentage, and nitrogen on saturated fatty acids (SFAs) and of pH and conductivity on the major MUFAs.

PSIV-B-16 Effects of Replacing Cottonseed Meal with Carinata Meal on Performance, Intake, and Digestibility in Backgrounding Beef Heifers Consuming a Corn Silage-Based Diet

Abstract The value of carinata, a non-food oilseed crop, has been demonstrated as a high-quality jet fuel alternative and successful cover crop in the southeastern U.S.; however, research is limited regarding carinata as an alternative for commonly used protein sources in livestock. Eighty-four Angus crossbred heifers were used in a generalized randomized block design to evaluate the effects of replacing cottonseed meal with carinata meal on performance, intake, and digestibility in backgrounding corn silage-based diet. Treatments included: corn silage only (C), corn silage + Brassica carinata meal (BCM) at 10% (CS-BCM10) or 20 % (CS-BCM20) inclusion, or corn silage + cottonseed meal at 10% inclusion (CS-CSM). Protein sources were mixed on an as fed basis with corn silage prior to delivery and provided ad libitum, with individual intake measured using the GrowSafe system. Data were analyzed using Proc Glimmix of SAS. An effect of treatment was observed for final body weight (BW; P < 0.01), average daily gain (P < 0.01), and gain to feed ratio (P < 0.01), where CS was least. Dry matter intake (DMI; P = 0.01) was greatest for CS-BCM10. No effect of treatment was observed for residual feed intake (P = 0.94), time ruminating (P = 0.32), or DMI as a percentage of BW (P = 0.10). Intake of nutrients was greatest (P < 0.01) for CS-CSM, except crude protein (CP), which was least (P < 0.01) for CS. Dry and organic matter digestibility was decreased (P < 0.01) in CS but did not differ from CS-BCM10, whereas CP digestibility was greatest (P < 0.01) in CS-BCM20, and neutral and acid detergent fiber digestibility was least (P < 0.01) for CS. Carinata performed similarly to cottonseed meal in backgrounding beef heifers fed a corn silage-based diet, thereby enhancing its value in the southeastern U.S.

Crop succession and its reflections on soybean performance

The fluctuations in yield and consequently in production occurred due to climatic adversities in the main producing states of Brazil. Farming has changed over time, and past scenarios have shown high exploitation of natural resources focusing on soil tillage and conventional seeding methods. This study aimed to determine the yield performance of soybean grown under 10 consolidated crop succession systems. The experiment was conducted during the 2018/2019 crop season, before the research project entitled “Sustainable production systems with better use of biological and natural resources, with treatments arranged in a randomized block design and four replications”. The treatments consisted of the following predecessor crops: Avena sativa, Avena strigosa, Triticum aestivum, Secale cereale, Brassica napus, Raphanus sativus, Avena strigosa + Raphanus sativus + Vicia sativa, Fallow, Avena strigosa + Lolium multiflorum, and Triticum aestivum – Fodder. Soybean was subsequently sown across winter crops. The succession that showed superior yield was Avena strigosa + Lolium multiflorum. This attribute was established by associating taller plants with the maximization of the number of grains per pod, hundred-grain mass, grain mass, and plant dry mass; in contrast, there was a lower emphasis on plant residue. The determining attributes for soybean yield were plant stand, plant height, the number of pods per plant, and total grain mass, with contrasts among groups composed of the succession of Avena sativa, Avena strigosa, Triticum aestivum, Secale cereale, and Brassica napus, distanced from Raphanus sativus, Avena strigosa + Raphanus sativus + Vicia sativa, Fallow, Avena strigosa + Lolium multiflorum, and Triticum aestivum - Fodder.

The importance of market signals in crop varietal development: lessons from Komboka rice variety

Growing high-yielding varieties is crucial for successful crop production and maximizing farmers’ net returns. One such example is IR05N221, locally referred to as Komboka rice variety, which was released in Kenya in 2013. On the one hand, Komboka can bridge the gap in rice imports since yields of existing rice varieties do not meet the increasing rice consumption levels of the Kenyan population. On the other hand, it has taken about seven years for Komboka to be appreciated by farmers, necessitating the need to understand farmer preferences when it comes to adopting a new improved variety. We used a mixed-method study approach by combining quantitative and qualitative data collected regionally and locally in both rainfed and irrigated ecologies. When compared to most of the other rice varieties under evaluation, Komboka was high-yielding, early-maturing, and had moderate tolerance to diseases in both rainfed and irrigated ecologies. However, farmers at the regional level ranked Komboka either at the same or lower rank in terms of sensory attributes. At the local level, farmers predominantly grew older and more aromatic Basmati 370 rice variety for sale, as it fetched them more money, with preferences for both men and women rice farmers being the same. Despite Komboka being a high-yielding variety, Mwea rice farmers’ perceptions and preferences for this improved variety were low. While Komboka was equally aromatic, the lack of a ready market dissuaded these farmers from widely preferring the new Komboka variety. We provide prerequisite information that can support the commercialization and promotion of the Komboka variety. We also show that widespread favourable perception of new varieties hinges on matching preferences between breeders’ efforts for improved rice productivity with farmers’ needs for market competitiveness in these new varieties.

Times and methods of black oat management on corn plantability

The importance of maintaining straw on the soil surface is a subject widely discussed and proven in the literature. However, the effects of this straw on planting efficiency and quality still lack information. In this sense, both time and method of the black oat management influence the permanence of the straw on the soil and, thus, can interfere in the next crop's germination and plantability of the seed drill. This study aimed to evaluate methods and times of black oat management and their implications on the plantability and development of the corn crop in succession in two harvests. A randomized block design with twelve treatments was used, consisting of the combination of three methods of management (crushed, rolled, and desiccated) and four times of management (0, 10, 20, and 30 days before the corn sowing) of black oat straw, arranged in a 3 x 4 factorial scheme, with four replications. The black oat management carried out 30 days before the corn sowing provides the highest corn emergence rate. Management methods that promote greater fragmentation of straw tend to offer less mechanical impediment to seedling development and result in a greater initial and final plant population.

Ultrasound, as a hypomethylating agent, remodels DNA methylation and alters mRNA transcription in winter wheat (Triticum aestivum L.) seedlings.

Any treatment that affects seed germination and seedling development is of paramount importance from an agricultural point of view since they are critical prerequisites for successful crop production. In present study, we have examined the after-effect of ultrasonication (at 30 kHz, 70 W for 5min) of winter wheat (Triticum aestivum L. cv. SE15) seeds on the early seedling growth and development, and accompanying changes in the DNA methylation and transcriptomic pattern in 7-day-old seedlings. We used mRNA-sequencing and whole genome bisulfite sequencing (WGBS) to identify significantly differentially expressed genes (DEGs), significantly differently methylated regions (DMRs) and genes (DMGs). Ultrasonication of seeds did not alter the germination rate but increased both the length and weight of roots and shoots of 7-day-old seedlings significantly by 23%-68% and 16%-28%, respectively. Analyzing the expression intensity of 107,891 genes, significantly differentially expressed sequences related mainly to starch biosynthesis, IAA biosynthesis, photosynthesis and TCA cycle pathways. The same pathways were also affected by DNA-methylation changes. DNA hypomethylation occurred in the global methylation profile after ultrasound treatment altering the accessibility of some genes for transcription. Transcriptomic changes suggested alterations in the crosstalk between IAA and sucrose signaling, enhancement of growth processes, and increased activity of nuclear transcription factor stimulating the transcription of genes having CCAAT motif in the promoter. In the present first whole genome level study, we have identified seed ultrasonication as a priming technique that can act as a hypomethylating agent and thereby is able to modify the mRNA transcription allowing enhanced seedling growth.

IMPORTANCE OF BIOFFERTLIZATION VIA RHIZOBIA STRAIN ON PEA (PISUM SATIVUM L.) PRODUCTION IN A STRESSED EDAPHO-CLIMATIC ENVIRONMENT, IN TUNISIA

Pea (Pisum sativum L.) is a nutritious leguminous rich source of protein. It plays an important role in crop rotation and contributes efficiently to soil fertility. Despite these nutritional, symbiotic and agronomic characteristics, pea cultivation areas are in regression and yield remain low. Abiotic and biotic constraints as well as the optimization of symbiotic nitrogen fixation are the main factors affecting the pea crop development. This work aimed to study the effects of inoculation with rhizobia having high potential solubilization of inorganic phosphorus on pea production under edapho-climatic stress conditions. Inoculation with rhizobia and phosphorus fertilization trials were performed in vitro at the laboratory and in vivo in fields at two experimental stations for three successive crop seasons characterized by contrasted precipitations regimes. The inoculation with both selected strains of Rhizobium (TAC and 12362) increased significantly the biomass nodular and improved the phosphorus content and phosphorus use efficiency (PUE) of pea plants. The phosphorus application induced symbiosis efficiency and increased nodulation and biomass production of pea. Regardless of the treatment, a highly significant effect of the season and site on the variability of pea production was recorded. Inoculation with rhizobia could substitute nitrogen and phosphorus chemical fertilizers for economic, ecological and sustainable agriculture.

At Which Spatial Scale Does Crop Diversity Enhance Natural Enemy Populations and Pest Control? An Experiment in a Mosaic Cropping System

The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven their efficiency. However, the impact of crop-richness continuity in space and time on pests and natural enemies at a landscape scale remains poorly studied. In a two-year study, we assessed the effect of crop richness (single crop vs. multiple crops) on pest and natural enemy abundance and spillover in a field experiment in north-east China. Overall, we found crop diversity had a limited impact on pest and natural enemy abundance at the spatial scale tested (0.025 vs. 0.2 ha). The total pest and natural enemy abundances were not different between single-crop and multi-crop plots in either year, and the community composition at the functional group level was mostly determined by the crop but not crop diversity. However, we found that crop diversity influenced the numeric response of ladybirds to aphids in wheat; their negative response (higher abundance where aphid abundance was lower, suggesting predation) was attenuated in multi-crop plots (no correlation of aphid and ladybird abundance, suggesting the use of alternative resources). This pattern was not found in maize. Finally, crop succession enhanced the spillover of ladybirds from wheat and maize to cotton plots but with limited benefits for aphid control. Because of these limited impacts, we hypothesized that crop diversity may benefit natural enemy populations and enhance pest control at larger spatial scales; while we found similar abundances of ladybirds between our small (0.025–0.2 ha) plots and in large (2 ha) close-by cotton fields, aphid abundances were more than ten times higher in large cotton fields. Our study highlights the need to accurately estimate the spatial scale at which crop biodiversity may benefit pest control, in relation to the ecology of the target pest and natural enemies.

Hydrogeochemical assessment of streamwater quality for its suitability for irrigation: the case of Manthong village, Kanglung (Bhutan)

Abstract Mountain streams/springs are the primary irrigation water resource in Bhutan Himalaya, besides supporting drinking and other domestic needs. Successful crop production implies an adequate supply of high-quality irrigation water, among other factors. Thus, this study was conducted to assess the suitability of spring-fed streamwater for irrigation use and evaluate hydrogeochemical processes that regulate streamwater chemistry at the Manthong village in Kanglung, Bhutan. The water samples were analyzed for temperature, pH, electrical conductivity (EC), turbidity, total dissolved solute (TDS) and major ions. Piper and Durov diagrams indicated that most samples are of the intermediate type and simple dissolution or linear mixing is the primary hydrochemical process regulating streamwater chemistry. All the measured physicochemical parameters were within the acceptable thresholds of the FAO guidelines recommended for agricultural use. Analytical results of the streamwater water quality indices, including EC, %Na, residual sodium bicarbonate (RSBC), sodium adsorption ratio (SAR), Kelley's ratio (KR) and permeability index (PI), revealed its suitability for irrigation use except for magnesium hazard (MH). The Irrigation Water Quality Index (IWQI) results confirmed that the WS-1 has no restriction as irrigation water; however, WS-2 falls under the high-restriction category. The findings of this study will serve as the baseline data and guide irrigation water management and sustainable irrigation development in the region.

Plant Attractants and Rewards for Pollinators: Their Significant to Successful Crop Pollination

Plant and pollination have a mutualistic relationship where both parties offer and gain benefits for each other. The plant-pollinator interactions resulted in successful crop pollination in which the plant received pollination services by animal pollinator to increase food production that eventually increase crop economic value. Overall, ecosystem is highly dependent on pollinator thus there is a need to review potential valuation method of crop production and analyse the current understanding of the value of pollination service towards the ecosystem as well as the traits plant offer and benefits that pollinators gain from the relationship. The attractant and rewards highly depending on each other. Plant often able to attract pollinators through traits like the shape, size and colours of flower, deception, scents as well as location. In the meantime, plant would provide a reward for pollinators that visited the flower which includes food from pollen and nectar that contains high nutritional value, energetic rewards to reduces energy cost of survival, protection and shelter against predator and not to forget breading, oviposition and mating sites inside the flower plant. The ecological relationship of plant and pollinator resulting in effective crop pollination if the attractant and incentives are significantly reliant on one another. With this review and current technological advancements, optimistically more deeper investigations in the interaction of pollinator and flowering plant can be conducted and best pollinator management approaches can be established to secure sustainable crops production

Fertilization With Laying Hen Manure and Economic Analysis in Caesar Weed (Urena lobata L.) Seed Production in Amazonas, Brazil

The Caesar weed (Urena lobata L.), produces a light-colored fiber used in the textile industry for the production of sacks, fabrics, and rugs. The bottleneck in the Caesar weed production chain is the seed production. Because Caesar weed grows in a floodplain for fiber production, it does not complete its growth cycler and produce seeds. Therefore, the seeds used in the state of Amazonas come from the Brazil state of extractivism in Pará, which increases the seed costs for fiber production. It is advantageous to develop production technologies that will produce large quantities of viable Caesar weed seed on land in the state of Amazonas. Fertilizer management is an essential element to the successful crop and seed production. Laying hen manure as an organic fertilizer is one of the most accessible fertilizers for the family farmer. It is produced in large volumes at a low cost. The purpose of this research was to evaluate the impact of different doses of laying hen manure on the production of Caesar weed seeds from the perspective of an economic analysis. The experiment was a randomized complete block design with five doses of laying hen manure (0, 5, 10, 15, 20 t/ha) and four replications. Seed productivity was evaluated from the economic point of view of fertilization. A dose of 12.7 t/ha of laying hen manure is recommended for the production of 890 kg/ha of Caesar weed seeds in low fertility soil with a very clayey texture (Souza, 2012).

Integrated modeling of crop and water management at the watershed scale: Optimizing irrigation and modifying crop succession

The expanded use of water-intensive crops, such as maize, has exacerbated soil drying and water scarcity in watersheds with large irrigated surfaces. As we face climbing drought risks, water can be conserved in such areas by adopting agricultural systems that limit water deficits at the watershed level. In this study, integrated modeling was used to assess how different approaches to cultivating irrigated maize influenced water balance in France’s Aveyron watershed, which experiences strong and recurrent water deficits. Ten-year simulations were performed using the MAELIA model, which can simulate at fine-scale spatial and temporal interactions among agricultural activities, the functioning of soil-crop systems, hydrological dynamics, and water resource management. Three specific scenarios were modeled in addition to the benchmark situation representing current management practices: 1) maize irrigation was carried out on an as-need basis, where all farms were equipped with a decision‑support tool for assessing water stress in real time; 2) maize monocultures were replaced by a wheat/maize succession; and 3) the two previous scenarios were combined. In the first two scenarios, irrigation withdrawal volumes declined substantially, eliminating approximately 30 % of the watershed’s water deficit due to a better scheduling of the irrigation to the needs and by the replacement of maize by wheat with lower water requirements. There was also a slight increase in river flow rates in the summer and a slight decrease in annual drainage. The third scenario went even further in lowering withdrawal volumes and increasing flow rates thanks to additive effects: withdrawal volumes declined by 28 %, and river flow rates increased by 4 %. This study demonstrated that combining water-saving practices with crop diversification holds promise for limiting water deficits in irrigated watersheds while having a negligible impact on crop yields. It also demonstrated the usefulness of a multiagent integrated modeling platform that can conduct simulations at fine levels of spatial and temporal resolution on both agronomic and hydrologic aspects

Residual effects of alkalized sewage sludge application on soil quality and sugarcane yield

ABSTRACT The acidification and loss of nutrients and organic matter in tropical soils are indicators of chemical degradation. In such a scenario, alkalized sewage sludge (SS) for fertilization and reclamation of soils is a promising alternative. Here, we evaluate the impact of SS on soil fertility, sugarcane nutrition and yield in three successive crops. The treatments consisted of five rates of SS (0, 10, 20, 30, and 40 t ha−1) and one treatment with mineral fertilizers. The soil characteristics, plant nutrition, and sugarcane yield were assessed. The results showed that SS increased the pH and the sum of bases, reducing exchangeable aluminum and improving chemical soil conditions. SS also increased soil organic matter (SOM), but SOM decreased over time. Likewise, the N and P contents in the soil were decreased with the successive crops. Sugarcane yield increased following SS rates and reduced with each crop cycle. The yields for plant cane, first ratoon, and second ratoon were 174, 94, and 74 t ha−1 at a rate of 40 t ha−1; these values were 75, 19, and 61% higher, respectively, than the mineral fertilization. SS can aid the reclamation of the chemically degraded soil, contributing to sugarcane nutrition and increased yields.

Heat of the moment: extreme heat poses a risk to bee-plant interactions and crop yields.

Extreme heat events threaten the development, functioning, and success of bee pollinators and crops that rely on pollinators for high yields. While direct effects of extreme heat and climate warming have gained more attention, the indirect effects on bees and crops remain largely unexplored. Extreme heat can directly alter the nutritional value of floral rewards, which indirectly contributes to lower bee survival, development, and reproduction with implications for pollination. Phenological mismatches between bee activity and crop flowering are also expected. Heat-stressed crop plants with reduced floral rewards may reduce bee foraging and nesting, limiting pollination services. Understanding how extreme heat affects bee-crop interactions will be essential for resilient production of pollinator-dependent crops in this era of climate change.