Crop Production Research Articles

Assessment of manganese accumulation in dryland wheat grains via plastic film mulching: Implications for human health risk in multi-site studies

Crop manganese (Mn) accumulation and the associated human health risks stemming from excessive intake of high Mn crop foods have attracted attention. However, there is limited information available concerning the impact of plastic film mulching (PFM) on Mn concentration in cereal grains and the health risks associated with Mn intake by the human body. Field experiments were conducted from 2014 to 2016 at seven sites in the drylands of a typical wheat-growing region in China to assess the effect of PFM on grain Mn concentration, Mn accumulation and distribution in winter wheat plants, and the potential risk of Mn intake and optimal grain intake for human health. The multi-site study results revealed that grain Mn concentration and bioavailability were significantly higher under PFM compared to no mulching. Similarly, PFM was found to enhance aboveground Mn accumulation at the anthesis stage by 17.5 %, Mn harvest index by 3.9 %, grain Mn accumulation by 28.9 %, and available Mn concentration in the soil by 10.9 %. The increased uptake and accumulation of Mn in wheat plants, leading to elevated grain Mn concentration, were primarily attributed to the improved availability of Mn and moisture in the soil under PFM treatment. Furthermore, a health risk assessment indicated that long-term consumption of whole wheat grains from PFM treatment could potentially pose a non-carcinogenic risk of Mn for children and adolescents residing in rural areas. Therefore, this study established upper limits for daily consumption of whole wheat grains based on the specific needs of local residents. The findings of this research underscore the potential health risks associated with consuming grain crops grown in PFM crop production systems.

Long-term experiments to identify response patterns of available soil nitrogen, rice, and soybeans to rice straw compost in a paddy-upland rotation field in Akita, Japan

ABSTRACT Compost application can enhance soil fertility and is consequently presumed to increase crop production in Japan’s paddy-upland rotation fields. This study aimed to evaluate the effects of rice straw compost (RSC) application on available soil nitrogen (Av-N) levels and rice and soybean plants in a paddy-upland rotation field using data obtained from a long-term field experiment. Data collected between 2005 and 2020 were analyzed from a long-term paddy rice – upland soybean rotation field. The experimental design employed a split-plot arrangement, with RSC application (with and without RSC) representing the whole plot, N fertilizer application (no nitrogen vs. standard fertilizer) representing the split-plot, and years representing the replication factor. The datasets included eight years of rice and soybean cultivation, and the chemical properties of postharvest soil spanned 16 years. The data was analyzed via analysis of variance. Applying RSC increased the Av-N concentration significantly by 63%–67%. The RSC application significantly increased the N concentration in rice shoots at the mature stage by 8%–12% but decreased it in soybean shoots after the seed emergence stage by 4%–8%. Consequently, the rice yield displayed clear responses to RSC application, whereas the soybean yield did not. The lack of soybean yield response might be due to an inhibitory effect of the Av-N gain attributable to the RSC application on biological nitrogen fixation. While applying compost can enhance Av-N content as well as rice productivity in paddy-upland rotation fields, its impact on soybean productivity requires careful evaluation.

Effect of Different Fertilization Strategies on Infestation of Brown Wheat Mite and Wheat Productivity

The brown wheat mite, Petrobia tritici, poses a significant threat to wheat fields. While fertilizers can increase crop productivity, imbalanced application may exacerbate plant susceptibility to pests. This study aimed to evaluate the impact of various NPK fertilization programs on P. tritici infestations over two consecutive cropping seasons. The results revealed significant differences in mite infestation among the treatment groups (p < 0.001). The lowest populations (1.1 and 3.0 mites/leaf) were observed in the treatments sprayed with phosphoric acid (at 0.75 and 1.00 cm/L), where the infestation appeared approximately 120 days after sowing; in contrast, it appeared early at 75 days in the other treatments. Conversely, treatments lacking potassium fertilizer presented the greatest degree of mite injury levels (49.5–57.7 mites/leaf). Although these treatments provided moderate leaf nutrition and crop yield, the highest nutritional content and total yield (10.49 and 9.71 1 t/ha for the two years) were observed in the treatment that received 224:70:100 kg fad−1 commercial fertilizers (=178:25:114 kg ha−1 NPK units) as soil fertilization, which was followed by the treatment with a foliar application of phosphoric acid (1.00 cm/L) with a total yield of 9.34 and 8.53 1 t/ha for the two years. In this treatment, the P. tritici density was moderately high at 9.40 and 6.32 mites/leaf over the two years, respectively. The consistency of P. tritici density and total yield ranking across both years indicated reliable estimates of the impact of fertilization. This study suggests that potassium sulfate application is crucial for reducing P. tritici density and that foliar phosphoric acid application instead of soil application reduces the number of P. tritici and delays its occurrence.

Effect of Conservation Agricultural Practices on Crop Yield and Soil Properties Under Sorghum [Sorghum bicolor (L.) Moench] — Black Gram [Vigna mungo (L.) Hepper] System in Rainfed Alfisol

ABSTRACT A long-term study was conducted to assess the effect of tillage (conventional, CT and minimum, MT) and residue retention treatments on crop yields, sustainable yield index (SYI), rain water use efficiency (RWUE) and soil properties under sorghum – black gram system in resource poor Semi-Arid Tropical (SAT) Alfisol at Hyderabad, India. The results revealed that when averaged over residue retention treatments, MT recorded 12.32 and 5.21% higher sorghum and black gram grain yield, 19.61 and 25.93% higher sustainability yield Index (SYI), and 12.27 and 5.15% rain water use efficiency (RWUE), respectively, over conventional tillage. Residue retention treatments (averaged over tillage treatments) S2 (cutting at 60 cm height for sorghum and 100% retention for black gram) and S1 (cutting at 35 cm height for sorghum and 50% retention for black gram) recorded 33.16 and 16.16, and 32.18 and 14.88% higher sorghum and black gram yield, respectively, over S0 (no residue) and also recorded 26.0 and 9.0, and 48.0 and 22.0% higher SYI over S0 in sorghum and black gram, respectively. Increase in RWUE under S2 and S1 over S0 was 33.19 and 16.23% in sorghum and was 31.4 and 14.53% in black gram. Higher residue retention maintained significantly higher soil organic carbon (SOC), significantly lower bulk density (BD) and significantly influenced potential of hydrogen (pH) and electrical conductivity (EC) at all the depths and also increased available nitrogen (N), phosphorus (P), potassium (K), manganese (Mn), iron (Fe), zinc (Zn) and copper (Cu) by 35.43, 24.55, 12.12, 57.6, 53.99, 51.46 and 13.76%, respectively. Thus, the results of the present study are highly useful in improving the crop yields, yield sustainability and soil properties. Therefore, the conservation agriculture practices can be a resource saving and higher crop production technology in the rainfed Alfisols.

Spatiotemporal Analysis of Open Biomass Burning in Guangxi Province, China, from 2012 to 2023 Based on VIIRS

Open biomass burning has significant adverse effects on regional air quality, climate change, and human health. Extensive open biomass burning is detected in most regions of China, and capturing the characteristics of open biomass burning and understanding its influencing factors are important prerequisites for regulating open biomass burning. The characteristics of open biomass burning have been widely investigated at the national scale, with regional studies often focusing on northeast China, but few studies have examined regional discrepancies in spatiotemporal variations over a long timescale in Guangxi province. In this study, we used the Visible Infrared Imaging Radiometer Suite (VIIRS) 375 m active fire product (VNP14IMG), combined with land cover data and high-resolution remote sensing images, to extract open biomass burning (crop residue burning and forest fire) fire points in Guangxi province from 2012 to 2023. We explored the spatial density distribution and temporal variation of open biomass burning using spatial analysis methods and statistical methods, respectively. Furthermore, we analyzed the driving forces of open biomass burning in Guangxi province from natural (topography, climate, and plant schedule), policy, and social (crop production and cultural customs) perspectives. The results show that open biomass burning is concentrated in the central, eastern, and southern parts of the study area, where there are frequent agricultural activities and abundant forests. At the city level, the highest numbers of fire points were found in Baise, Yulin, Wuzhou, and Nanning. The open biomass burning fire points exhibited large annual variation, with high levels from 2013 to 2015 and a remarkable decrease from 2016 to 2020 under strict control measures; however, inconsistent enforcement led to a significant rebound in fire points from 2021 to 2023. Forest fires are the predominant type of open biomass burning in the region, with forest fires and crop residue burning accounting for 76.82% and 23.18% of the total, respectively. The peak period for crop residue burning occurs in the winter, influenced mainly by topography, planting schedules, crop production, and policies, while forest fires predominantly occur in the winter and spring, primarily influenced by topography, climate, and cultural customs. The results indicate that identifying the driving forces behind spatiotemporal variations is essential for the effective management of open biomass burning.

Unraveling the intriguing potential of protein-rich microbial biostimulants for horticultural crops

Nutritional security and minimizing the impact of farming practices on the environment are major challenges in modern farming systems. Currently, the horticulture sector is growing fast and moving towards sustainability and profitability. Indiscriminate and improper use of chemical inputs to ensure high yields of horticultural products could lead to significant contamination of soil and water bodies. Under these circumstances, farmers must optimize their input management to reduce pollution and preserve the economic margin by following sustainable production practices. The use of precision horticulture techniques is more sustainable than conventional to intensive farming methods. Among the various eco-friendly inputs, plant biostimulants are highly effective and can enhance plant growth and production as well as mitigate the adverse effects of abiotic stressors. Protein Hydrolysates (PHs) are a significant class of plant biostimulants based on amino acid and peptide mixtures. Because of their beneficial effects on crop performance, PHs has drawn increased amounts of attention recently. Compared with other biostimulants microbial biostimulants are more prevalent in crop production. A new approach is the formulation of a mixture of plant growth-promoting microorganisms/microbe-derived metabolites and protein hydrolysates as single biostimulants, to nourish the soil, plants and microbes. This review presents a thorough summary of recent research on the postulated modes of action of PHs and microbial biostimulants in horticultural crops. Furthermore, this study highlights the potential of protein hydrolysates and microbial biostimulants and the potential of the protein-rich microbial biostimulants to make horticulture more profitable and to safeguard the environment.

Enhancing the sustainability of cowpea production through the integrated use of fish effluents and animal manure

AbstractThe integration of aquaculture and agriculture in arid and semi‐arid environments is crucial for maximizing water and land productivity, especially considering the increasing global water scarcity and the simultaneous use of water for crop and fish production. A greenhouse study was conducted to determine the effects of fish effluent on the growth, yield parameters, and yield of cowpea (Vigna unguiculata). The experiment involved 13 fertilization treatments, including three types of irrigation water (river water—control, Nile tilapia (Oreochromis niloticus), African sharp‐toothed catfish (Clarias gariepinus), four fertilizers (poultry, cattle, and sheep manures at 10 t ha−1), recommended rate of inorganic fertilizer (150 kg ha−1 of NPK 6‐20‐10), and six mixed treatments with fish effluent and 50% of the applied rate of manure alone (5 t ha−1). The combined use of C. gariepinus effluent + 50% poultry manure significantly increased stem diameter, nodules per plant, pods per plant, and seed yield compared to NPK treatments. The shortest days to reach 50% flowering were obtained with the effluent of O. niloticus + 50% sheep manure, C. gariepinus/O. niloticus + 50% poultry manure, and 10 t ha−1 poultry manure. However, fertilization treatments did not significantly influence the number of branches, pod and root length, number of pods per plant, 100‐seed weight, and leaf chlorophyll concentrations. This study suggests that fish effluents, when combined with manure, can improve plant growth and seed yield, providing a cost‐effective alternative to inorganic fertilizers for smallholder farmers.

Seasonal Behaviour of Arrivals and Prices of Major Crops in Krishi Upaj Mandis of Chhattisgarh, India

Chhattisgarh state is famous for its forest wealth and mineral resources and there is abundant production of crops. According to total area of crops, Paddy (77.47 percent) and Chickpea (5.43 percent) are major crops of Chhattisgarh state. Arrivals and price data (Year 2014-15 to 2023-24) of major crops were collected from website of Chhattisgarh state Mandi Board. The study was observed that the peak arrivals & price of paddy were started in the same months November to January in both market (KUM, Bemetra & KUM, Bhatapara) except peak price season starts in August to October with narrow difference in KUM, Bhatapara. In case of Chickpea, the peak arrivals and price started in the month of March to May & September to November, respectively. The Price stability of both crops (paddy & Chickpea) was higher in KUM, Bhatapara as compared to KUM, Bemetra. The less price fluctuation of paddy as compared to chickpea in Chhattisgarh state due to purchasing directly to farmers by the Government with Minimum Support Price (MSP) and also provided the Bonus. The study was suggested that the economic development of farmers in state, the government should purchase agricultural products other than paddy and cooperate in setting up dal mills & processing units. Necessary steps should be taken to increase of marketable surplus and development of community level threshing area. The study was importance in knowing the market behaviour and price fluctuation during the peak season and the major reason behind. The studies also throw light on the aspect how to enrich the economic condition of the farmers.

Daily Light Integral and Far-Red Radiation Influence Morphology and Quality of Liners and Subsequent Flowering and Development of Petunia in Controlled Greenhouses

Petunia stands as the top-selling bedding plant in the U.S., and improved lighting control in greenhouses holds the potential to reduce crop production time and optimize crop quality. This study investigated the impact of four distinct daily light integral (DLI) conditions with and without supplemental far-red (FR) radiation on the growth of petunia liners and subsequent development of finish plants. Two experiments were conducted in spring (9 April to 18 June 2021) and winter (28 October 2021 to 6 January 2022). Petunia cuttings were rooted in a common environment and then transferred to four greenhouse sections with different DLI treatments: 6, 9, 12, and 15 mol·m−2·d−1 for four weeks. Within each DLI condition, half of the plants were exposed to 28 μmol·m−2·s−1 supplemental FR radiation for 16 h daily (equivalent to 1.61 mol·m−2·d−1 light integral). The number of flower buds and open flowers were tracked daily. Representative liners were destructively harvested and evaluated after four weeks of lighting treatments. The remaining plants were transplanted and moved to a common DLI condition of 15 mol·m−2·d−1 for an additional three weeks before being destructively harvested and evaluated as finish plants. The primary finding reveals the promoting effect of DLI on flowering, branching, morphology, and biomass accumulation of petunia liners, with many effects persisting into the finish stage. A threshold DLI of 9 mol·m−2·d−1 was identified, as lower DLI (6 mol·m−2·d−1) resulted in extensive stem elongation, rendering the plants unmarketable. Higher DLI levels were found to be optimal in terms of flowering and morphology. Supplemental FR accelerated flowering by up to three days in the summer experiment and up to 12 days in the winter experiment. However, FR had limited impact on the number of flower buds and open flowers, branching, and shoot and root weight of the finish plants. Interactions between DLI and FR were observed on some parameters, whereby FR effects were more pronounced under lower DLI. Overall, both higher DLI and supplemental FR exhibited beneficial effects, but DLI had a more pronounced effect. Thus, DLI during petunia liner production appears more important than adding FR. This study well simulated the commercial propagation and production of petunia plants, providing practical insights for decision-making regarding lighting strategies.

Characterization of Plant Growth Promoting Rhizobacteria and Their Benefits on Soybean Growth

Background: Soybean is the most important legume in the world and its seeds contains 40% protein and 20% oil. In recent years, more attention has been paid to the use of plant growth-promoting (PGP) rhizobacteria as a biofertilizer alternative to chemical fertilizers, which may pose risks to the environment. The rhizobia inoculation of soybean is a sustainable practice to induce atmospheric nitrogen fixation and subsequently improve crop productivity and soil fertility. Methods: In this study, 19 indigenous rhizobia isolated from soybean were tested in vitro for their plant growth-promoting properties (PGPR), while genotypic characterization included sequencing of the 16S rRNA gene. Result: Morphological characterisation has shown that all of the isolates were rod-shaped gram negative bacteria. The sequencing has shown that 12 out of 19 isolates belong to the genus Pseudomonas, four of which belong to P. fluorescens species. Isolates which belong to the Pseudomonas genus have shown the highest ability of indole-3-acetic acid synthesis, phosphorous solubilization and along with isolates SGN6, SGN7 and SGS4 (Sphingomonas sanguinis) potassium solubilisation too. All the isolates from Pseudomonas genus as well as those belonging to B. japonicum species have shown the protease synthesis abilities while amylase synthesis abilities was observed only in the isolate SAK2 (P. chlororaphis). The most efficient strains in in vitro biological nitrogen fixation assay belong to Pseudomonas and Rhizobium genera. Most of the isolates were positive to the organic acid production while all of them have shown the ability of the exopolysaccharide production.

Improved Agronomic Practices on Enhancement of Quality Forage Production for Livestock Farming

The lack of nutrient-rich fodder and forage is one of the problems of livestock farming. Adequate tillage operations, timely and suitable water management, weed management, insect pests and disease management, fertilizer management, seeding at the proper time and seed rate, timely harvesting, and other agronomic techniques can all help to increase the nutritional content and yield of fodder and forage crops. A number of research and review papers have been systematically reviewed in this study. The use of tillage practices such as primary, secondary, conventional, and deep tillage enhances dry matter and yield of green fodder as compared to zero tillage. The organic matter (OM) content and dry matter (DM) of fodder crops are increased by regular and appropriate irrigation. The DMD (dry matter digestibility) and CP (crude protein) contents of early harvested forages are higher than those of late harvested forages. The application of nitrogen promotes crop development and growth, increasing the production of green fodder and improving its quality. Intercropping is essential for increasing the yield of fodder crops. Compared to sole cropping of maize and cowpea, the yield is found higher in intercropping of maize + cowpea. The production and quality of fodder are decreased by late seeding. The management of insect pests and diseases enhances the production and quality of fodder and forage. Thus, we draw the conclusion that fodder and forage crops production and their quality parameters are greatly influenced by agronomic practices.

Nitrogen-Fixing Gamma Proteobacteria Azotobacter vinelandii—A Blueprint for Nitrogen-Fixing Plants?

The availability of fixed nitrogen limits overall agricultural crop production worldwide. The so-called modern “green revolution” catalyzed by the widespread application of nitrogenous fertilizer has propelled global population growth. It has led to imbalances in global biogeochemical nitrogen cycling, resulting in a “nitrogen problem” that is growing at a similar trajectory to the “carbon problem”. As a result of the increasing imbalances in nitrogen cycling and additional environmental problems such as soil acidification, there is renewed and increasing interest in increasing the contributions of biological nitrogen fixation to reduce the inputs of nitrogenous fertilizers in agriculture. Interestingly, biological nitrogen fixation, or life’s ability to convert atmospheric dinitrogen to ammonia, is restricted to microbial life and not associated with any known eukaryotes. It is not clear why plants never evolved the ability to fix nitrogen and rather form associations with nitrogen-fixing microorganisms. Perhaps it is because of the large energy demand of the process, the oxygen sensitivity of the enzymatic apparatus, or simply failure to encounter the appropriate selective pressure. Whatever the reason, it is clear that this ability of crop plants, especially cereals, would transform modern agriculture once again. Successfully engineering plants will require creating an oxygen-free niche that can supply ample energy in a tightly regulated manner to minimize energy waste and ensure the ammonia produced is assimilated. Nitrogen-fixing aerobic bacteria can perhaps provide a blueprint for engineering nitrogen-fixing plants. This short review discusses the key features of robust nitrogen fixation in the model nitrogen-fixing aerobe, gamma proteobacteria Azotobacter vinelandii, in the context of the basic requirements for engineering nitrogen-fixing plants.

The effects of financial development on crop productivity: ARDL evidence from Indian agriculture

Purpose This work aims to empirically investigate the effects of financial development on crop productivity of India. Design/methodology/approach Time series data such as crop production index, International Monetary Fund’s (IMF) financial development index, gross domestic product (GDP) per capita, arable land, rural population, trade openness and physical capital from 1980 to 2020 was used. The autoregressive distributed lag (ARDL) bounds testing approach of cointegration was used to determine the long-run equilibrium relationship between the selected time series. Also, ARDL long- and short-run coefficients were estimated to examine the effects of selected variables on crop productivity. Furthermore, to establish the robustness of results, long-run estimators such as fully modified least squares and the dynamic least squares were also used. Finally, using the vector error-correction model, causality between the selected time series was examined. Findings The ARDL cointegration test confirmed the existence of long-run equilibrium relationship among agricultural productivity, financial development, capital formation, GDP per capita, arable land, rural population and trade openness. The estimated long-run elasticities from all the three techniques and the short-run elasticities of ARDL have consistently suggested that the elasticity of financial development is higher (1.55% and 1.40%, respectively) in explaining the crop productivity of India. The short-run causality estimates indicated the presence of positive bidirectional causality between crop productivity and financial development and seven positive unidirectional causal relationships between the selected variables. Practical implications Agricultural credit being an important non-land input and essential for overall growth and sustenance of agricultural sector, the policymakers should ensure the overall development of its financial sector which will reduce the intermediation, informational and other transactional costs associated with agricultural credit. This will possibly result in timely availability and access to adequate and low-cost credit from institutional sources. Originality/value Though extensive research is available on the effects of financial development on economic growth, limited research is available concerning the impact of financial development on crop productivity, especially for an emerging economy like India. For India, predominantly studies have investigated the impact of farm credit on crop productivity but have not exclusively examined the effects of financial development on agricultural productivity. Therefore, this study not only adds to the empirical literature but also provides new evidence on the nexus between financial development and crop productivity by examining the effects of financial development on crop productivity using the composite financial development index developed by the IMF using the ARDL bounds test for cointegration and other econometric estimators.

Plastic mulching enhances maize yield and water productivity by improving root characteristics, green leaf area, and photosynthesis for different cultivars in dryland regions

Uneven precipitation during the growing season and frequent seasonal droughts on the Loess Plateau in Northwest China adversely affect crop production and water use efficiency. While plastic mulching (PM) has been used to alleviate water stress, few studies have examined the traits maize cultivars need to adapt to the altered water environment under PM and achieve high yields. A two-year field experiment was conducted to assess the root characteristics and aboveground growth traits of three widely used high-yielding maize cultivars—Zhengdan 958 (ZD), Huanong 138 (HN), Heboshi 122 (HBS)—under no mulching (NM) and PM conditions. Among the three cultivars, HBS had the highest root system indices—root length density (RLD), root surface area density (RSD), and root biomass—in the topsoil (0–40 cm), followed by ZD and HN under both NM and PM conditions. Under NM, HBS_NM treatment exhibited strong water absorption, improving photosynthesis and yield, making it suitable for drought conditions. Under PM, topsoil moisture increased significantly, with root system indices increasing by 22.5–36.1 % for RLD, 30.2–36.1 % for RSD, and 25.2–36.5 % for root biomass across the cultivars compared to NM. While ZD_PM did not have the highest root system indices under PM, it exhibited higher green leaf area index (4.5–7.5 %), chlorophyll content (2.8–8.6 %), and photosynthetic rate (6.0–14.5 %), resulting in the highest aboveground biomass and yield among the treatments. These findings suggest ZD is better adapted to the enhanced soil moisture under PM. Future research should focus on breeding genotypes that thrive under PM conditions, emphasizing traits such as larger leaf areas and higher photosynthetic rates to boost crop productivity in rainfed areas.

Complementary effects of pollination and biocontrol services enable ecological intensification in macadamia orchards.

In many crops, both pollination and biocontrol determine crop yield, whereby the relative importance of the two ecosystem services can be moderated by the landscape context. However, additive and interactive effects of pollination and biocontrol in different landscape contexts are still poorly understood. We examined both ecosystem services in South African macadamia orchards. Combining observations and experiments, we disentangled their relative additive and interactive effects on crop production with variation in orchard design and landscape context (i.e., cover of natural habitat and altitude). Insect pollination increased the nut set on average by 280% (initial nut set) and 525% (final nut set), while biocontrol provided by bats and birds reduced the insect damage on average by 40%. Pollination services increased in orchards where macadamia tree rows were positioned perpendicular to orchard edges facing natural habitat. Biocontrol services decreased with elevation. Pest damage was reduced by higher cover of natural habitat at landscape scale but increased with elevation. Pollination and biocontrol are both important ecosystem services and complementary in providing high macadamia crop yield. Smart orchard design and the retention of natural habitat can simultaneously enhance both services. Conjoint management of ecosystem services can thus enable the ecological intensification of agricultural production.

Ascophyllum nodosum Extract Improves Olive Performance Under Water Deficit Through the Modulation of Molecular and Physiological Processes.

The olive tree is well adapted to the Mediterranean climate, but how orchards based on intensive practices will respond to increasing drought is unknown. This study aimed to determine if the application of a commercial biostimulant improves olive tolerance to drought. Potted plants (cultivars Arbequina and Galega) were pre-treated with an extract of Ascophyllum nodosum (four applications, 200 mL of 0.50 g/L extract per plant), and were then well irrigated (100% field capacity) or exposed to water deficit (50% field capacity) for 69 days. Plant height, photosynthesis, water status, pigments, lipophilic compounds, and the expression of stress protective genes (OeDHN1-protective proteins' dehydrin; OePIP1.1-aquaporin; and OeHSP18.3-heat shock proteins) were analyzed. Water deficit negatively affected olive physiology, but the biostimulant mitigated these damages through the modulation of molecular and physiological processes according to the cultivar and irrigation. A. nodosum benefits were more expressive under water deficit, particularly in Galega, promoting height (increase of 15%) and photosynthesis (increase of 34%), modulating the stomatal aperture through the regulation of OePIP1.1 expression, and keeping OeDHN1 and OeHSP18.3 upregulated to strengthen stress protection. In both cultivars, biostimulant promoted carbohydrate accumulation and intrinsic water-use efficiency (iWUE). Under good irrigation, biostimulant increased energy availability and iWUE in Galega. These data highlight the potential of this biostimulant to improve olive performance, providing higher tolerance to overcome climate change scenarios. The use of this biostimulant can improve the establishment of younger olive trees in the field, strengthen the plant's capacity to withstand field stresses, and lead to higher growth and crop productivity.

The Effectiveness of The Agricultural Investment Environment in Supporting the Production of Strategic Crops in Iraq for The Period From 2003-2021

Maximizing the effectiveness of the agricultural investment environment for all its basic inputs from the economic and human resources available in Iraq represents a qualitative breakthrough in the production of strategic crops, therefore, the research problem came from the weak production of strategic agricultural crops in Iraq in quantity and quality, due to the ineffectiveness of the agricultural investment environment, as a result of the lack of government support, the deterioration of the infrastructure of the agricultural sector, and a shortage of monetary capital, Finally, the scarcity of water resources, the problem was treated using the analytical method, thus, the research aims to demonstrate the importance of developing the agricultural investment environment and increasing government support and its impact on the production of strategic agricultural crops, the research concluded that Iraq possesses most of the basic inputs to the agricultural investment environment, but it lacks efficient management and optimal use, in addition to climate change, which has helped increase drought and desertification, the research also concluded that agricultural policy in Iraq includes obliging the investor to an agricultural plan in which the cultivated area is determined under the pretext of limited the capacity of the stores and the amount of strategic water storage despite Iraq’s need for strategic crops and thus the state’s attempt to meet the increasing demand for strategic crops t-hrough imports, which makes Iraq subject to the fluctuations of the global market and the depletion of hard currency, the researcher recommends efficient and optimal exploitation of natural, financial and human resources and keeping pace with scientific and technological progress in the production of strategic crops. In conclusion, the research included the deductive approach through the method of analytical description to advance the agricultural investment environment in Iraq. Paper type: Research paper.

Simulating PFAS transport in effluent-irrigated farmland using PRZM5, LEACHM, and HYDRUS-1D models.

Application of wastewater effluent to agricultural lands can serve as a sustainable approach to meet irrigation and nutrient needs for crop production. While nitrogen and phosphorous loadings can be effectively managed, concerns have been raised regarding the fate of emerging contaminants, including per- and polyfluoroalkyl substances (PFAS), which are widely detected in wastewater effluent. The objective of this paper was to evaluate the ability of three unsaturated flow and transport models, Pesticide Root Zone Model 5 (PRZM5), LEACHM, and HYDRUS-1D, to predict the distribution of PFAS in the soil profile at the Pennsylvania State University Living Filter site, which has received daily wastewater effluent applications for several decades. The models were modified to include adsorption at the air-water interface (AWI), which has been shown to be an important factor governing PFAS transport and phase distribution in the vadose zone. Simulations showed that PRZM5 did not accurately reproduce the observed perfluorooctanesulfonic acid (PFOS) behavior, which was attributed to the "tipping bucket" approach used for water flow that results in the disappearance of AWI during water flow. In contrast, both LEACHM and HYDRUS-1D captured the observed retention of PFOS and perfluorooctanoic acid (PFOA) over a 50-year simulation period. Due to differences in the approach used to calculate the AWI area, LEACHM predicted greater accumulation of PFOS and PFOA at the AWI compared to HYDRUS-1D. These findings indicate that mathematical models that directly account for unsaturated water flow and adsorption at the AWI are able to provide reasonable predictions of long-term PFAS leaching resulting from land application of wastewater effluent.

The Application of a Foliar Spray Containing Methylobacterium symbioticum Had a Limited Effect on Crop Yield and Nitrogen Recovery in Field and Pot-Grown Maize.

In this study, the effectiveness of an inoculant containing a nitrogen (N)-fixing microorganism (Methylobacterium symbioticum) was evaluated on maize (Zea mays L.) grown both in the field (silage maize) and in pots over two years (2021 and 2022). The field trial included the following two treatments: with (Yes) and without (No) the inoculant. The pot experiment was designed as a factorial arrangement with two factors: the application of the inoculant (Yes and No) and N applied to the soil (0, 0.4, 0.8, and 1.6 g pot-1). In the field, total dry matter yield (DMY) did not differ significantly between treatments, although the average DMY was higher in the inoculant treatment. In pots, the total DMY varied significantly across all N rates but was only significantly affected by the inoculant application in 2022. N fixation estimates in the field were 58.8 and 14.5 kg ha-1 for 2021 and 2022, respectively, representing 23.7% and 9.1% of the N recovered in the aboveground plant parts. In pots, the estimated fixed N values were -49.2 and 199.2 mg pot-1 in 2021 and 2022, respectively, which corresponded to -5.2% and 18.5% of the N found in the aboveground plant parts. Considering the average values obtained across the four cultivation conditions, there was a positive outcome for the treated plants. However, these values cannot be considered significant when compared to nitrogen removal in maize crops. A commercial product should provide an unequivocal and quantitatively relevant contribution to plant nutrition, which did not appear to be the case. Thus, for this inoculant to provide reliable guarantees of positive outcomes for farmers and become a useful tool in promoting more sustainable agriculture, further studies appear necessary. These studies should aim to determine in which crops and under what cultivation conditions the application of the inoculant is truly effective in enhancing N fixation and improving crop productivity.

Choline supplementation reduces cadmium uptake and alleviates cadmium toxicity in Solanum lycopersicum seedlings

Sustainable plant production in soil polluted with heavy metals requires that novel strategies are developed for the benefit of humans and other living things. Cadmium (Cd) is a common heavy metal pollutant for plants, and there is limited information on the use of exogenous bio-regulators to reduce the accumulation and toxic effects of Cd pollution in plants. Choline is an endogenous quertarnary amine that is known to improve stress tolerance in plants, while its mechanism of action in certain conditions is yet to be determined. This study investigated the effects of foliar choline supplementation (10 mM) on Solanum lycopersicum seedlings exposed to Cd application (50 mg/L in soil). The seedlings were randomized to five groups: Control (E1), Cd stress (E2), Choline supplementation after Cd stress (E3), Choline (E4), and Choline supplementation before Cd stress (E5). Following the applications, the Cd content, growth and development parameters (chlorophyll content, fresh and dry weight), oxidative stress parameters (H2O2 and MDA contents), as well as antioxidative defense system (SOD, GSH, AsA, and TPC contents) were analyzed. Choline supplementation after Cd stress reduced the enhanced Cd content in roots by 38% but did not alter it in leaves (p > 0.05) compared to the Cd group. Choline supplementation before Cd stress decreased Cd content both in roots by 87.5% and in leaves by 50%. Choline supplementation after and before Cd stress increased fresh and dry weights in both roots and leaves. While the Cd group (E2) increased the H2O2 level and SOD activity, no remarkable change was observed in H2O2 levels in all choline supplementations (E3, E4, E5). Therefore, lipid peroxidation (MDA) was not observed in choline supplementation before Cd stress (E5), however, when the choline was applied after Cd stress (E3) MDA content was reduced by 40% compared with the Cd stress group (E2). Choline supplementations after and before Cd stress (E3, E5) increased AsA content by 30%, while the Cd group (E2) decreased it by 60% compared with the control group (E1). Choline supplementations before Cd stress (E5) increased TPC by 33%, while the Cd group (E2) decreased it by 18%, moreover, when choline was applied after Cd stress (E3), no change was observed compared to the control group. These data suggest that choline prevents inhibition of plant growth due to Cd toxicity by reducing Cd uptake. The results provided in the present study are likely to enhance the quality and efficiency of crop production in heavy metal-polluted areas.