Low Soil Fertility Research Articles

Effects of Farmyard Manure and Nitrogen Fertilizers on Yield and Yield Components of Low Land Rice (Oryza sativa L.) on Vertisols of Fogera District, Northwestern Ethiopia

Rice (Oryza sativa L.) is a major cereal crop in Fogera district; however, the current yield is decreased due to low soil fertility status as a result of continuous cultivation, inadequate use of organic and inorganic fertilizers. Hence, a field experiment was conducted at Fogera National Rice Research and Training Center (FNRRTC) during the 2021 cropping season to determine the effects of farmyard manure and nitrogen fertilizer on yield and yield components of lowland rice on vertisols of Fogera district. The treatments were laid out as factorial combination of three levels of FYM (0, 5, and 7.5 t ha-1) and four levels of Nitrogen (0, 46, 92, and 184 kg ha-1). The experiment was arranged at (RCBD) with three replications. The phenological, yield and yield components of rice data were collected during the growth period. All collected phenological, yield and yield components of rice data were analyzed by using SAS software (version 9.4). Analysis of the results revealed that application of FYM at 7.5 t ha-1 combined with 92 kg N ha-1 increased grain yield by 218.25% compared to the negative controls. The highest rice grain yield (7533.1 kg ha-1), biomass yield (14553.1kg ha-1), number of grains per panicle (153.27) and harvest index (51.89%) were obtained from the application of 7.5 t ha-1 FYM with 92 kg ha-1 N. Therefore, combined applications of 7.5 t ha-1 FYM with 92 kg ha-1 N is the recommended treatment that economically feasible for rice production and soil fertility improvements on the Vertisols of the study area, which provided the net benefit of (166,838.02ETB ha-1) with an acceptable MRR of 3122.99%.

Maize seed inoculated with Azospirillum brasilense as strategy to improve photosynthetic nitrogen use efficiency in the Amazonian periphery

In the Amazonian region of Brazil, the combination of different inoculation forms of Azospirillum brasilense and N rates has not been studied for its effect on photosynthetic N use efficiency and yield in maize plants. The effects of inoculation forms of A. brasilense and N rates on photosynthetic N use efficiency and maize yield were evaluated. Two field trials were conducted, combining four N rates (0 to 180 kg ha−1) with different inoculation forms of A. brasilense (seed, leaf, or control). Photosynthetic N use efficiency (photosynthesis per unit leaf N) was taken at the beginning of tasseling stage, while yield and N use efficiency components were evaluated at physiological maturity. Photosynthesis and specific leaf N increased with increasing N rates, regardless of inoculation forms. Azospirillum-inoculated seeds, along with 114 kg ha−1 of N provided the maximum yield (6.0 Mg ha−1). Without N, seed inoculation increased yield by 33% and photosynthesis by 31% compared to the control. Averaged across N rates, seed inoculation increased photosynthetic N use efficiency by 17%–24% compared to the control. Azospirillum-inoculated seeds improved N use efficiency compared to the control under low N available. The results show that the Azospirillum-inoculated seeds could potentially decrease N rates from 180 to 114 kg ha−1 of N, while increasing yield by 9%. Besides, Azospirillum-inoculated seeds could enhance photosynthetic N use efficiency in a sustainable manner on low-fertility soils. Therefore, the benefits of the A. Brasiliense drive a sustainable agriculture by improving yield and reducing the need for N inputs.

Assessment of soil resources of agricultural landscapes in Turkestan region of the Republic of Kazakhstan based on agrochemical indexes

Abstract Natural and climatic features of the soil cover formation of Turkestan region of the Republic of Kazakhstan are identified by a set of hydrological and bioclimatic factors serving as important environment-forming functions, which are reflected in the landscape organization of the territory. When assessing soil resources of agricultural landscapes, integrated index of soil fertility was applied – the “soil index,” which takes into account the reserves of humus, mineral elements, and hydrolytic acidity. Based on monitoring observations (1996–2019) of soil fertility in agricultural landscapes (agricultural lands) of Turkestan region, assessment of soil resources was performed, which showed that in general, the generalized “soil index” ranges from 1.086 to 4.800 units depending on natural features of the territory. It is found that the “soil index” in agricultural landscapes is significantly less than its maximum value (20.000 units), which suggests a pronounced humus deficiency, showing low soil fertility in all agricultural landscapes. To assess the soil resources of agricultural landscapes in Turkestan region, a new approach was applied, which is based on the assessment of energy costs for the soil formation process, which enables to quantitatively reflect the radiation balance of the earth surface, heat, and moisture supply of agricultural land for 1941–1960 and 2001–2020. The indicators applied are subject to the law of vertical zonation and change from the mountain to the arid zone, where the potential energy costs for soil formation range from 82.2–101.9 to 129.4–135.5 kJ/cm2, and natural energy costs energy costs for soil formation from 17.2–21.7 to 121.7–125.2 kJ/cm2.

Typology of smallholder maize farmers in South-Kivu, Eastern D.R. Congo: implications in improving farming practices and markets

Understanding the typology of smallholder maize farmers is crucial to elucidate the diversity in local farming systems, and therefore, devise effective interventions and policies that maximize the impact of agricultural innovations in South-Kivu province, eastern Democratic Republic of Congo (DRC). This study aimed at characterizing maize farmers in South-Kivu province and clustering them based on various socioeconomic and agronomic factors to identify specific production constraints and devise more effective interventions. A household survey among 300 South-Kivu maize farmers allowed to identify four distinct clusters based on farm size, land use, income, and agricultural technology adoption. The clusters ranged from resource-poor smallholder (Types 1 and 2) to medium-resource semi-innovative producers (Type 3) and highly equipped innovative farmers (Type 4). Key discriminative factors included total farm size, maize farm size, farming experience, access to agricultural credit, income, and innovation adoption rate. This study revealed specific constraints for each cluster, including low soil fertility, poor weed management, low market access, and labor scarcity. This study’s findings demonstrate the value of farm typology in guiding targeted interventions to address specific constraints and improve maize productivity, and suggest specific strategic directions for research and development projects in rural areas of the South-Kivu province.

Enhancing herbicide adsorption in low-fertility soil using sugarcane biochar: Insights from Imazapic dynamics

Biochar amendment has emerged as a potential solution for preventing, remediating, and mitigating agricultural compound pollution. This groundbreaking technique not only improves crucial soil properties like porosity, water retention capacity, cation exchange capacity, and pH, but also intricately impacts the interaction and retention mechanisms of polluting molecules. In this study, we investigate the dynamic of the herbicide Imazapic when subjected to applying pyrolyzed biochars, specifically at temperatures of 300 and 500 °C, within the context of a low-fertility soil characterized as dystrophic Yellow Ultisol (YUd) in a sugarcane cultivation area in Igarassu-PE, Brazil. The biochars were produced from sugarcane bagasse by pyrolysis process in a muffle furnace. In laboratory conditions, with saturated soil columns under steady-state, analyses of the mechanisms involved in interaction and transport and determining hydrodispersive parameters for Imazapic were performed by the two-site nonequilibrium transport model using the CXTFIT 2.0 program. Samples of YUd soil amended with biochar pyrolyzed at 300 °C presented a negligible interaction with Imazapic. However, adding biochar pyrolyzed at 500 °C (BC500) to the soil samples enhanced the adsorption coefficient and improved the interaction with Imazapic. This research points out that biochar produced from agricultural waste biomass, such as sugarcane bagasse specifically pyrolyzed at 500 °C, offers a potential means to adsorb herbicides, reducing their leaching to deeper layers of the amended soils and the risk of groundwater contamination and potential environmental negative impacts.

From chocolate to palm oil: The future of Indonesia's cocoa plantations.

Indonesia is the world's third largest cocoa producer, but production is decreasing since 2011. We revisited cocoa farmers for an environmental assessment in Luwu Timur, Sulawesi, 7months after a socio-economic survey on cocoa certification outcomes and observed many cocoa plantations being converted into oil palm and maize. Including our field data as well as secondary data on commodity prices and yields, we outline reasons for cocoa conversion, potential consequences for biodiversity, and assess the future outlook for the Indonesian cocoa sector. Low cocoa productivity, volatile cocoa prices and higher revenue for oil palm, among others, drive land-use change. If shade trees are cut during cocoa conversion, it may have negative implications for biodiversity. Solutions to low soil fertility, omnipresent pests and diseases, and stable producer prices are needed to increase profitability of cocoa and prevent conversion of cocoa agroforests to oil palm monocultures.

Soil Fertility Level In The Aek Kundur River Area Regardless Of Factory Waste Disposal

Soil fertility is the ability of the soil to provide the nutrients needed by plants in adequate quantities and in a form that can be absorbed by plant roots. The aim of this research is to determine the level of soil fertility in the Aek Kundur river area regarding factory waste disposal in Lingga Tiga Village, District. West Bar. This research was carried out in June 2024 in Lingga Tiga Village, Bilah Hulu District, Labuhanbatu Regency with an altitude of 28 meters above sea level with coordinates N: 98022'44.34" E: 02032'34.23". Analysis of the physical and chemical properties of soil was carried out at the Laboratory of the Faculty of Agriculture, University of North Sumatra using an exploratory-descriptive survey method. Research results on the physical properties of the soil in Lingga Tiga Village have a clayey clay texture and in Liga Tiga Village have a clay texture. Furthermore, the chemical properties of the soil in Lingga Tiga Village have criteria, namely neutral pH, low organic C, moderate P2O5 and low soil fertility status in the Aek Kundur river area against factory waste disposal. For this reason, fertilization treatment is needed to improve soil fertility status.

Influence of «ORGANIC MAX» organic fertilizer on soil condition in Zakarpattia

With a shortage of traditional organic fertilizers and a constant increase in the cost of mineral fertilizers, it is important to find alternative environmentally friendly sources of nutrients. The effectiveness of the new organic fertilizer «Organic MAX», made on the basis of lignite (brown coal) and chicken droppings in the conditions of Zakarpattia region, which provides positive changes in the agrochemical criteria of the soil, has been proposed and studied. Under the influence of bird droppings, the humic substances of lignite go into a physiologically active state and effectively act as plant growth stimulants and sources of nutrients. According to the results of field studies, there is an increase in the effectiveness of this fertilizer with an increase in the content of animal waste: «Organic MAX–20» (lignite + 20% chicken droppings) and «Organic MAX–30» (lignite + 30% chicken droppings). It was found that the application of this fertilizer at a rate of 1 t/ha provided an increase in the content of organic soil matter (humus) by 0.05% for pure lignite, by 0.19% for Organic MAX–20 and by 0.66% for Organic MAX–30. There was also an increase in the content of nutrients: easily hydrolyzed nitrogen by 14.1–55.9 mg/kg; mobile phosphorus compounds at 64.5–109.3 mg/kg; mobile potassium compounds at 64.9–125.5 mg/kg. The effective effect of the fertilizers applied for the next year was revealed despite the high level of nutrient removal by a crop such as corn. The humic component is a nutrient medium for soil bacteria. The active work of microorganisms is the main link in the process of humus formation. After fertilization, there is an improvement in the water-physical properties of the soil, an increase in microbiological activity, as well as a decrease in the negative impact of adverse factors on the development of plants. On acidic soils, first of all, liming must be carried out before fertilizing. The type of this fertilizer is chosen for a specific crop after conducting agrochemical analyzes of the soil. The most effective application of these fertilizers on low-humus low-fertile soils, as well as non-structural ones, since they contribute to the optimization of soil properties. Its use is economically and environmentally feasible. It is possible to recommend environmentally friendly organic fertilizer «Organic MAX» for use in organic farming, the popularity of which in Ukraine is growing every year, to resume soil fertility.

Synergistic Effects of Microbial Gibberellic Acid and Vitamins on Onion (Allium cepa L.) Yield, and Quality in Low-Fertility Soil

Onion is one of the most popular vegetables that play a major role in boosting immunity against diseases. As a result of the successive population increase, many farmers resort to excessive use of chemical plant growth enhancers to increase the crop's productivity, which causes many health and environmental problems and reduces the sustainability of the soil. Microbial phytohormones and vitamins are safe, eco-friendly, and effective natural solutions to increase the crop's productivity and maintain the soil health at the same time. To our knowledge, until know there is no information about the roles of microbial gibberellic acid (GA3), and vitamins on the growth and quality traits of onions. Two field experiments were conducted during two consecutive winter seasons in a sandy calcareous soil farm. Two treatments were in the main plot (without and with microbial GA3), and six were in the sub-plot (control, chemical thiamine, ascorbic acid, riboflavin, and microbial ascorbic acid and riboflavin). Plant growth parameters including plant height, fresh weight, leaf number, bulb diameter, and neck diameter were recorded. Onion yield and their quality traits of sugar content, protein, antioxidants, vitamin C, phenols, flavonoids, and NPK were measured. The major findings revealed that plants treated with applications of microbial GA3 or vitamin treatments significantly improved the onion yield, phenotypic, physiological, and biochemical characteristics in both seasons. In the majority of the measured parameters, the microbial ascorbic acid treatment outperformed the other vitamin treatments. The combination of foliar microbial GA3 spray and vitamins, especially microbial ascorbic acid, and microbial riboflavin, produced the high onion yield, growth and quality traits of plant height, number of leaves, fresh weights, bulb diameter, sugar content, vitamin C, total antioxidants, total phenols, and flavonoids during both seasons. The application of microbial GA3 in combination with microbial vitamins as foliar spraying are promising eco-friendly, cheap, plant bio-stimulators that could be used safely in the field, especially under low-fertility soil, for good growth, yield, and high-quality onions.

Agronomic performance of cowpea cultivars in first crop in Southwest of Minas Gerais, Brazil

The cowpea (Vigna unguiculata (L.) Walp.) is well adapted to high temperatures, water deficits and low fertility soils, being widely cultivated in regions less favorable to common beans. Its grains are rich in proteins, vitamins and minerals, representing an important food source and a promising alternative for producing protein at low cost, in a short space of time, given the precocity of its cycle. However, in the state of Minas Gerais there is only a recommendation for one cowpea cultivar, the Poços de Caldas cultivar. In addition to being quite old, it is no longer found in crop production fields. The aims of study was to evaluate the agronomic performance of cowpea cultivars and to recommend cultivars adapted to cultivation in edaphoclimatic conditions of Southwest Region of Minas Gerais State, Brazil. The experiments were carried out in Passos city, Minas Gerais State, Brazil, during the first crop period, in 2021/2022 and 2022/2023 years, with 10 commercial cowpea cultivars, in a randomized block experimental design, with five replications. The mass of a thousand seeds and the grain index correlated directly with the yield. Cultivars with the lowest grain yields promoted the highest pod lengths and number of grains per pod. The best morphophysiological results for cowpea were obtained in 2021/2022 year. The most adapted cowpea cultivars for period of first crop in edaphoclimatic conditions of Southwest Region of Minas Gerais State, Brazil, were BRS Novaera, BRS Guariba, and BRS Xique-Xique and least indicated was BRS Marataoã. More studies are needed to consolidate cowpea cultivation in the Southwest Region of Minas Gerais, mainly in second-crop crops.

Effects of farmyard manure (FYM) and blended NPSB fertilizer rate on growth and yield of potato (Solanum tuberosum L.) in Gewata, Kaffa, southwest Ethiopia

Potato (Solanum tuberosum L.) is an essential crop for nutrition and food security and generating income to small-holder farmers in Ethiopia. Productivity of the crop is, however, limited by poor nutrient management practices and low soil fertility. In most parts of potato growing areas of Ethiopia, soil are deficient in macro (nitrogen, phosphorus and sulfur) and micro nutrients (boron) which are known to affect production and productivity of potato. A field trail was accompanied to determine the growing response of potatoes ’Belete varieties’ to combine the treatment of farmyard manure and blended NPSB (nitrogen, phosphorous, sulfur and boron) fertilizer at Gewata, southwest Ethiopia during 2019/2020 main cropping season. The variables are laid out four level of farmyard manure (0, 5, 10 and 15 t/ha) and four level of blended NPSB fertilizer (0, 50, 100, and 150 kg/ha). The treatments were organized in a completely randomized block design with three replications using a 4x4 factorial layout. SAS (version 9.4) was used for data were analyzed. The finding indicate that, combined application of FYM (farmyard manure) with NPSB significantly (p<0.01) affects plant height, average mass of tuber, number of marketable and unmarketable tuber per hill, and tuber yields per plot. It also significantly (p<0.05) influenced days to flowering, maturity, and tuber number per hill. The highest tuber weight (99.33 g), tuber number per hill (9.67), and yield (34.10 kg) per plot were recorded from the mixed fertilization of 15 t FYM with 150 kg/ha NPSB mineral nutrients. As a current finding, it can be stated that the combined use of FYM (15 t/ha) and NPSB blended fertilizer could improve potato growth and yield in the study area (150 kg/ha).

The effect of biostimulants and red mud on the growth and yield of shallots in post-unlicensed gold mining soil

Abstract Shallot production in West Kalimantan is still low. Land that has the potential for the development of shallots is the soil from post-unlicensed gold mining (PUGM). The soil at PUGM was exploited very extensively and can be used to develop shallots, but it is obstacled by low pH values and nutrient content. This research aims to investigate the impact of biostimulants and red mud on the growth and yield of shallots. The experiment was carried out in two stages: (1) investigated the ratio of the red mud and PUGM soil at the laboratory and (2) investigated the biostimulants and red mud effect on two varieties of shallots in a screen house. For the second experiment, there were three factors. The first factor was the biostimulant (0, 2, 3, and 4%); the second factor was the dose of red mud (0, 2, and 4 tons ha−1); and the third factor was the shallot varieties (Bima Brebes and Tajuk). The results of the first research indicated that the application of the red mud and PUGM soil in a ratio of 1:500 and 1:1,000 had a pH of 7.88 (slightly alkaline) and 7.24 (neutral), respectively. The second study found that a 2% concentration of biostimulant increased plant height and tuber count by 23.78 cm and 6.55 tubers, respectively. The Bima Brebes variety produced better fresh tubers weight clump−1 and dry tubers weight clump−1 than the Tajuk variety, with, respectively, 42.08 g (7.36 tons ha−1) and 32.60 g (5.71 tons ha−1). These findings show that the use of the biostimulants and red mud together in integrated management can help shallots grow and produce more, especially on PUGM land that has obstacles with low soil fertility. This research contributes to the identification of sustainable solutions for agricultural development in environments that have experienced severe land degradation, such as unlicensed gold mining activities.

Assessment of the Influence of zaï, Stone Rows, and Organo-mineral Fertiliser on Soil Properties and Groundnut Yields Performances in Sudan Sahelian Zone of Burkina Faso

Groundnut occupies a vital position in oilseed crop production in Burkina Faso, with current production at 630,526 tonnes. However, its production faces threats from drought and low soil fertility. This study aims to determine the influence of zaï, stone rows, ridge tillage, and mineral fertilisation on soil health and on groundnut yields performances in Sudan Sahelian zone of Burkina Faso. Experimental treatments were distributed randomly following a Fisher block design, comprising four treatments and five replications, in the village of Sandogo. Data on soil properties, plant growth, and yields were analysed using variance analysis in R software. The results indicate significant influences of the treatments on carbon content, nitrogen content, phosphorus content, pH values, soil moisture content, soil carbon dioxide release, and soil macrofauna. Moreover, notable effects were observed on the number of nodules, drier nodule weight, number of leaves and branches, pod load, pod and straw yields, and the weight of 100-pods. The highest carbon content (0.857; 0.861%), nitrogen content (0.081%; 0.087%), phosphorus content (7.488; 7.735 mg.kg-1), pH values (6.43; 6.54), and soil moisture content (24.80; 25.27%) were recorded in the homogeneous group of zaï and zaï associated to stone rows. The highest carbon dioxide release (2863.33 ppm) was recorded in plots treated with stone rows. Ants were the most widely encountered macrofauna, whereas no earthworms were recorded. The highest performance in terms of the number of nodules (84.76; 87.88), dry nodule weight (0.0893; 0.0886 g/plant), number of leaves (40; 40), number of branches (6; 6), pod load (25; 25), weight of 100-pods (112.90; 111.98 g), straw yields (1673.28; 1664.87 kg.ha-1), and pod yields (2122.32; 2161.96 kg.ha-1) were achieved with zaï and zaï combined with stone rows. Zaï and zaï combined with stone rows can therefore be used as effective alternatives to improve groundnut production in the Sudan Sahelian zone of Burkina Faso in a context of climate change, while protecting the environment.

Pertumbuhan dan Produksi Jagung pada Berbagai Varietas dan Dosis Trichokompos

The productivity of maize as a staple food needs continuous enhancement through various methods, one of which is fertilization. The exploration of diverse fertilizers is expected to help reducing the reliance on increasingly expensive synthetic fertilizers. Fertilization is a crucial practice to improve soil fertility on marginal lands. It refers to land with productivity limitations due to factors such as low soil fertility, poor soil texture, or environmental conditions that do not support optimal plant growth. By providing additional nutrients through trichocompost fertilizer, plants are expected to grow better even under suboptimal soil conditions. This study aims to investigate the effect of trichocompost fertilizer dosage on various maize varieties grown on marginal land. The research was conducted using an experimental design with plot sizes of 3 x 5 meters. The method employed was a factorial Randomized Block Design (RBD) with two factors. The first factor was the dosage of trichocompost (control, 3 tons/ha, and 6 tons/ha), and the second factor was maize varieties (Sinhas1, Nasa29, JH36, Bisi18, and Pioneer27), with each treatment repeated three times, resulting in a total of 45 experimental plots. The parameters tested included plant height, number of leaves, ear height, days to flowering, and fresh ear weight. The results showed that trichocompost had a significant effect on two parameters: the increase in plant height and the number of leaves at 49 days after planting (DAP), as well as the fresh ear weight. The maize variety significantly affected almost all tested parameters.

Nutrient status and soil fertility index as a basis for sustainable rice field management in Madiun Regency, Indonesia

<p>Agricultural development, specifically for crops, contributes significantly to national development. However, problems with water and low soil fertility are obstacles to this development. This study evaluated the nutritional status and soil fertility index as the basis for determining the direction of rice field management in Madiun Regency, East Java, Indonesia. The research method was conducted by surveying the soil characteristics followed by laboratory analysis. Soil samples were collected using stratified proportional sampling from 19 land units with 31 samples. The soil fertility index was determined using a principal component analysis test and calculated by dividing the weights by the minimum soil fertility index indicators. The study results show that the nutritional status of total N in the study area is low to high (0.13%–0.59%) and total P is very low to very high (12.18–73.66 ppm), whereas the status of exchangeable K is very low to very high (0.01–0.67 cmol.kg<sup>−</sup><sup>1</sup>), Cation Exchange Capacity is low to high (12.8–36.0 cmol.kg<sup>−</sup><sup>1</sup>), and organic carbon is low to very high (1.98%–6.54%). The soil fertility index ranges from medium to extremely high. The influential indicators are total P, total N, exchangeable K, and organic carbon. It is recommended that the rice field management system implement a “sustainable agricultural intensification” system that combines the two systems “intensification” and “sustainable agroecosystem.” This system still uses proportional inorganic and organic fertilizers (manure, compost, and agricultural waste).</p>

Land Suitability Evaluation of Cocoa (Theobroma cacao L.) Production Areas in Davao City, Philippines

With the growing demand for cocoa, local farmers and other key players of the cocoa industry were encouraged to boost production to secure supply. However, after many decades of cocoa production, soil fertility and available cultivation areas are shrinking. Land suitability evaluation was conducted in areas grown with cocoa in Davao City, Philippines to determine the current suitability and soil-related constraints for cocoa production intensification and expansion. Using the environmental lapse rate, temperature of the area was determined and suitability were evaluated using Food and Agriculture Organization framework with the aid of QGIS software. Based on the result, six soil series were identified as suitable for cocoa. These included the Cabantian, Bolinao (Inayangan), Bolinao (Paquibato), Miral, Tugbok and undifferentiated soil. Cabantian, Miral and Bolinao (Inayangan) were moderately suitable with limitations in slope and soil fertility. Bolinao (Paquibato) was moderately suitable with limitations in soil depth and sloping topography. Tugbok was marginally suitable due to low soil fertility and slight limitation in slope. Undifferentiated soil was moderately suitable with sloping topography, shallow depth and soil fertility constraints. The six suitable soil series had moderate to marginal limitations. The constraints to cocoa production are manageable to some extent.

The Efficacy of Organic Amendments on Maize Productivity, Soil Properties and Active Fractions of Soil Carbon in Organic-Matter Deficient Soil

The decline in soil productivity due to intensive cultivation, unbalanced fertilization and climate change are key challenges to future food security. There is no significant research conducted on the effect of organic amendments on soil properties and active carbon fractions in organic-matter deficient soils under changing climate. Biochar (BC) is a stabilized organic amendment produced from organic materials and is increasingly recognized as being able to improve soil health and crop productivity. The present study was conducted to determine the efficacy of compost (CM) (0.5%, 1%) (w/w) and animal manure (AM) (0.5%, 1%) (w/w) alone and combined with 3% (w/w) biochar, on soil carbon fractions, soil properties, and crop growth in a low-fertile soil. The results revealed significant increased 46% plant height, 106% and 114% fresh and dry shoot weight respectively, and 1,000-grain weight increased up to 40% when 3% BC with 1% CM was applied, compared to a control. Similarly, substantial increases in 69% soil organic matter, and 70% carbon pool index were observed at 3% BC, and under 3% BC with 1% CM increased 11% microbial biomass carbon compared to the control. Overall, the results suggest that 3% BC addition along with 1% CM and AM (1%) had greater potential to improve the soil carbon pool, microbial biomass, and soil health, all of which will ultimately enhance maize yield when grown in low-fertility soil. The application of BC, CM, and AM are a viable green approach, that not only boosts crop yields and improves soil properties and but also contributes to a circular economy.

Divergent effects of long-term fertilization on the carbon management index across soil profiles in key Chinese croplands

Evidence for the variability of the carbon (C) management index (CMI) across surface and subsurface soil layers due to long-term fertilization in diverse agroecological settings is inadequate. Thus, our study aimed to explore the variations in soil organic C (SOC), CMI, and its response ratio (RR-CMI) along soil profiles (0–60 cm) across four croplands in China. These croplands represented two high-fertility sites in Gongzhuling (GZL) and Chongqing (CQ) and two low-fertility sites in Zhengzhou (ZZ) and Qiyang (QY). We evaluated various treatments: control (CK; no fertilizer), inorganic fertilizer (NPK), NPK combined with standard manure (MNPK), and 1.5 times the standard rate of manure and NPK (1.5MNPK). The results indicated a significant increase in SOC content across all depths, ranking as 1.5MNPK > MNPK > NPK > CK, with ranking for the pattern observed across sites as GZL > CQ ≈ QY > ZZ. This led to the most substantial increases, reaching 107, 86, 105, and 62 % more than CK across the soil profile (0–60 cm) under 1.5MNPK across all sites. Moreover, the same treatment showed a significantly higher CMI at 0–60 cm compared to CK, with increases of 37, 19, 65, and 25 % for ZZ, QY, GZL, and QY, respectively. Notably, for the low-fertility soils (ZZ and QY), a higher CMI was observed in the 0–20-cm soil layer), whereas the opposite was true for the high-fertility soil (GZL). Consequently, low-fertility soils exhibited a higher RR-CMI in the 0–20-cm soil layer, whereas the high fertility site (GZL) showed a higher RR-CMI in the 40–60-cm soil layer, suggesting differential accumulation and loss of SOC regulated by soil depth and inherent site fertility. Partial least squares regression analysis further indicated that soil and climatic factors predominantly influenced CMI under long-term fertilization in typical Chinese soils. In conclusion, the long-term application of manure combined with inorganic fertilizer promotes SOC sequestration and enhances CMI, presenting a viable management strategy for enhancing soil quality in the studied regions.

Assessment of wheat genotypes for spot blotch (Bipolaris sorokiniana Sacc.) resistance under artificial epiphytotic conditions in the inner terai of Nepal

Spot blotch, caused by (Bipolaris sorokiniana Sacc.) is a significant fungal disease leading to economic losses in wheat (Triticum aestivum), especially in regions with low soil fertility and warm, humid climates, such as the inner Terai of Nepal. A field experiment was conducted at the National Maize Research Program (NMRP), Rampur, Chitwan, during winter of 2021/022 with an aim of identifying wheat genotypes with spot blotch resistance under artificial epiphytotic conditions. Each genotype was sown in a single 2-meter long row alongside susceptible check genotypes (Agra and Morocco) at every 20th row. Aqueous spore suspension of B. sorokiniana was applied twice in border rows during the booting stage at 15-day intervals. Disease severity was assessed four times at five-day intervals using a double-digit scale based on the percentage blighted area on the flag and penultimate leaf, and the area under the disease progress curve (AUDPC) was calculated. The results categorized 43 genotypes as resistant, 127 as moderately resistants, 135 as moderately susceptible, 66 as susceptible, and 7 as highly susceptible based on AUDPC. Cluster analysis identified cluster 3 comprising 17 genotypes as superior in terms of disease resistance as well as agronomic parameters. NRN-34 emerged as the top-ranked genotype within this cluster, followed by NAL-73, NAL-94, NAL-12, NRN-34, NAL-57, NAL-43, NAL-82, and NAL-35, exhibiting lower AUDPC values and higher yield-attributing character values. This study will aid breeders in developing spot blotch-resistant and high-yielding wheat varieties by incorporating the identified promising genotypes into further breeding programs.

Optimizing bioenergy sorghum productivity and nutrient removal in Illinois: Impact of nitrogen fertilization under diverse marginal conditions

Context or problemBioenergy sorghum (Sorghum bicolor L. Moench) is a promising crop for contributing to the United States bioenergy supply. However, the varying limitations of the marginal lands targeted for its cultivation present a management challenge. ObjectiveThis two-year study aimed to investigate how the limitations associated with marginal cropland impact the effects of nitrogen fertilization on the yield of bioenergy sorghum and the uptake of 11 macro- (N, P, K, Ca, Mg, and S) and micronutrients (Fe, Mn, Zn, Cu, and B). MethodsThe study contrasted prime cropland in central Illinois (Urbana) with three marginal cropland sites in southern (Ewing) and central Illinois (Fairbury and Pesotum). These marginal cropland sites are characterized by varying limitations, including low soil fertility (P and K limitations), leaching and erosion, and flooding, respectively. Four nitrogen rates (0, 56, 112, and 168 kg N ha−1) were tested under eight environments. ResultsThe average yields and ranges of sorghum biomass were 20.2 (17.0–23.2) Mg ha−1 in Urbana, 18.1 (13.1–19.8) Mg ha−1 in Ewing, 13.8 (9.0–17.3) Mg ha−1 in Fairbury, and 23.3 (14.6–33.0) Mg ha−1 in Pesotum. Optimal N rates were 56 N in Pesotum and 112 N in Urbana, Ewing, and Fairbury. Tissue macronutrient contents in Urbana were generally higher than in the marginal croplands, while micronutrient contents did not show discernible trends. Increasing N rate generally correlated with the macronutrient removal except in Ewing. ConclusionComparable sorghum biomass yields were observed between prime and marginal croplands (averaging 18.3 Mg ha−1), but optimal N rates varied between 56 N and 112 N. This suggests that yield gaps can be narrowed by applying the optimal N rates for the respective locations. However, increased removals of macronutrients, especially P and K, with increasing yields indicate the need to revise fertilizer recommendations, particularly for soils deficient in these nutrients. Implications or significanceOur study suggests that while sorghum production on marginal cropland is feasible, N management needs to be adapted to the unique limitations associated with various types of marginal cropland.