Low Soil Fertility Research Articles

Chickpea (Cicer arietinum L.) growth, nodulation, and yield as affected by varieties, Mesorhizobium strains, and NPSB fertilizer in Southern Ethiopia.

A significant legume crop in Ethiopia, chickpeas (Cicer arietinum L.) have several advantages, including high nutritional value and the capacity to improve soils deficient in nitrogen through biological nitrogen fixation using several endosymbiotic Mesorhizobium spp. strains. However, the host variety, the soil's capacity to hold nutrients, and the endosymbiont's innate physiological traits all affect how efficient the strains are. The primary obstacles to its cultivation in the research area are inadequate agronomic methods and low soil fertility [low nitrogen (N), low soil organic matter (OM), low accessible phosphorous (P), sulfur (S), and boron (B)], which results in ineffective nodulation. To evaluate the effects of NPSB fertilization and inoculation, a field experiment was carried out in Buchach Kebele's Cheha area during the primary cropping season of 2021/22. The trial included two chickpea kinds (Local and Arerti), two NPSB levels (zero and 121 kg NPSB ha-1), and four levels of Mesorhizobium strains (CP-M41, CP-EAL 029, CP-M20b, and un-inoculated control). A randomized complete block design (RCBD) was used to organize the treatments in a factorial form with three replications. In comparison to the single application and the control, the interaction impact of strains, NPSB fertilizer, and variety greatly increased nodulation parameters, growth parameters, yield, and yield components. The Arerti variety combined with the CP-M41 Mesorhizobium strain and NPSB fertilizer had the maximum grain production (3177.16 kg ha-1). It yielded 15.96%, 24.06%, and 37.93% more than the Arerti with CP-M41 strain, Arerti with NPSB, and the control treatments, respectively. The partial budget analysis of the study treatments showed that the Arerti variety with the combined application of 121 kg NPSB ha-1 and Mesorhizobium strain CP-M41 inoculation produced the highest net return (102,092.6 ETB ha-1) with an acceptable marginal rate of return (618%). It has been found that the CP-M41 strain and the Arerti variety, when combined with 121 kg NPSB ha-1 application, is a suitable treatment combination to achieve increased chickpea crop yield and profit in the studied area. However, the results need further validation in the farmer's field before recommending to farmers.

USO DEL ENSILADO DE SORGO VARIEDAD TOP GREEN Y VARIEDAD CAÑA DULCE PARA LA PRODUCCIÓN DE LECHE EN SISTEMAS DE PEQUEÑA ESCALA

<p><strong>Background</strong>. Sorghum is a crop that stands out as an alternative to maize due to its higher drought tolerance and lower soil fertility demand. <strong>Objective</strong>. To evaluate the productive response of lactating cows fed maize silage (<em>Zea mays</em>) in substitution with sorghum silage (<em>Sorghum bicolor</em> L.). <strong>Methodology</strong>. The research was carried out in the central highlands of Mexico, in the farmer of a small-scale dairy family. Nine cows were used, distributed in three 3X3 Latin squares with test periods of 14 days, of which 12 were for adaptation of the animals to diets and 2 d to the collection of samples. The treatments were: 1) Top Green = 5 kg DM sorghum silage cv Top Green + 5 kg DM maize silage; 2) Caña Dulce = 5 kg DM sorghum silage cv Caña Dulce + 5 kg DM maize silage; 3) Maize silage = 10 kg DM maize silage (testigo). The study included the productive behaviour of the cows, feed composition and feeding costs. Treatment data were analysed with a split-plot arrangement. <strong>Results</strong>. Inclusion of sorghum silage in the diet reduced dry matter intake (P<0.05), but did not affect average production (22.9 kg/day) and milk composition of cows (P>0.05). There were no differences (P>0.05) for variables related to the nutritional value of the silages. Although there were no significant differences in animal response variables, economic analysis showed that the inclusion of sorghum silage increased feed costs by 15% due to lower dry matter yields. <strong>Implications</strong>. Sorghum has been proposed as a resilient alternative to maize especially in drought stress scenarios, when the availability of quality forages decreases and grain and forage prices increase. <strong>Conclusions</strong>. Although feeding costs were higher, sorghum silage can be a substitute for maize silage.</p>

Use of nitrogen-fixing plants to improve planted forest soil fertility and productivity in New Zealand: A review

Background: Planted forests with low fertility soils are likely to require increased inputs of nitrogen (N) to satisfy increasing productivity demands. The use of N fertilisers will become more challenging due to their increasing cost and the risk of unwanted environmental impacts. Nitrogen-fixing plants may provide an alternative option to chemical fertilisers that is not only cheaper but has a lower greenhouse gas footprint. Methods: Information on N-fixing plants was collated from available literature, focusing on species previously associated with planted forests as well as other exotic N-fixing trees and New Zealand native plants not used in commercial planted forests. Results: Benefits to planted forest growth in New Zealand by N-fixing plants have been proven in only a few cases. Lupinus arboreus Sims was used in the 1970s and 1980s to increase N inputs in a planted Pinus radiata D.Don coastal forest, and improved P. radiata productivity was demonstrated. Productivity gains ceased when a blight disease infected the lupin population. Many N-fixing plants have been shown to tolerate low fertility soils and establish in planted forests, but there is limited information on their N contribution to the soil, and whether this N contribution increases P. radiata productivity. Such N-fixing plants include Lotus species, clover (Trifolium species) and weeds such as gorse (Ulex europaeus L.) and broom (Cytisus scoparius (L.) Link), which are commonly found in association with P. radiata forests. New Zealand native N-fixing shrubs may be suitable but there is limited information available describing N-fixation or forestry management for native plant species. Conclusions: Nitrogen-fixing plants are a valuable resource, which when managed properly could be used for enhancing productivity. Issues with pests and disease, and limited knowledge regarding the management of N-fixing species, restricts adoption in planted forests. Well-designed research is needed to assess impacts on whole forest system N cycling as well as selection of appropriate plant species for use in planted forests without unintended consequences such as competition for soil moisture or light. This research needs to be integrated with forest management and delivered as practical options to ensure success.

Comparative Efficacy of Weed Management Practices on Grain and Straw Yields of Wheat

Wheat is central to Afghanistan's food security. It accounts for 76 percent of the annual grain cereal harvest and 57 percent of the country's total food crop production. Several factors, such as low-yielding varieties, low soil fertility, low-quality agrochemicals, widespread pest and disease infestations, and widespread distribution of weeds, are the leading causes of low wheat productivity in the country. The current study was conducted at the Student Research farm of the Faculty of Agriculture at Kabul University to determine the overall effects of weeds on wheat grain and straw yields and to evaluate and compare different weed management practices in the wheat field. After applying the weed management practices, among the treatments, T1, T3, and T4 showed only 8.3, 5, and 2.3 percent weed populations, respectively, compared to the untreated control. Regarding grain and straw yields, mechanical control (hand weeding) ranked first with a grain yield of 4,867 kg/ha, followed by T1 (4,580 kg/ha), T3 (4,513 kg/ha), T2 (4,133 kg/ha), and T5 (3,416 kg/ha), respectively. The difference in straw yield among the treatments was not significant; however, mechanical control ranked first (7,103 kg/ha), followed by T1 (6,783 kg/ha), T3 (6,700 kg/ha), T2 (6,207 kg/ha), and T5 (5,280 kg/ha), respectively. The study findings concluded that by eliminating weeds, wheat grain and straw yields could be increased by an average of 30 and 26 percent, respectively. As broad-leaved weeds are widely distributed in the wheat fields, applying relative herbicides such as 2,4-D is more effective and recommended for all cultivation methods.

The influence of farm resources and management decisions on the severity of Striga infestation and maize productivity in western Kenya

AbstractThe control of Striga is of critical importance for smallholder farmers cultivating maize and other cereals in the western region of Kenya. Therefore, advanced knowledge and analysis is needed to understand farmers' resource endowment and decision making with regards to crop management, and the possible effect on Striga infestation and crop productivity. The overall objective of the study was to understand the role of resource endowment and allocation decisions on Striga infestation and maize productivity and offer effective and locally adapted options in western Kenya. The study used semi‐structured questionnaires, focus group discussions and resource flow mapping to identify farm resources and key management decisions that are critical in management of Striga on smallholder farms. Soil was sampled from fields of selected farms and taken to the laboratory for analysis including Striga seed counts. In the fields, Striga shoots counts, and maize yield were recorded. Socio‐economic variables such as land size, household income, labour availability, were used to construct a farm typology and assign farmers to different resource groups (RGs). Our results showed that household diversity leads to different land‐use patterns, resource‐use intensity and agricultural management practices which affect soil fertility and Striga infestation. Poor‐resourced farmers tend to be associated with poor crop and soil management which results in maize fields with low soil fertility and high level of Striga infestation. Soil organic carbon showed a strong negative association with Striga infestation. Improving soil fertility is, therefore, the central component of any integrated and sustainable Striga management approaches, and technological solutions to address Striga and soil fertility issues, and they must be tailored to the farm and field diversity. The inclusion of legumes is highly recommended either as rotation or intercropping depending on land availability. Where possible, farmers may use mulch from previous crop residues to suppress weed emergence and prevent flowering and seed setting. Hand weeding though tiresome, remains a low‐cost effective method to control Striga especially in areas where fields are small as in western Kenya.

Perception and Knowledge of Rice Value Chain Actors on the Effect of Improved Practices on Yield and Milling Characteristics of Rice in the Sagnarigu and Kumbungu Districts of Ghana

This study presents findings from a comprehensive survey conducted between January and March 2021, aimed at elucidating the agricultural practices and perceptions of rice farmers, processors, and marketers in the Sagnarigu and Kumbungu districts of the Northern Region in Ghana. The research sought to gather essential data on improved techniques employed in rice cultivation, milling, and marketing, as well as understand the perceptions surrounding these practices within the local farming communities. Employing a multi-stage sampling methodology, primary data were collected through face-to-face interviews with 134 rice farmers, 82 processors, and 22 marketers. Key findings revealed that a significant proportion (54.7%) of farmers preferred cultivating local rice varieties such as Moses, Bumbass, Mandii, Bazolgu, Salimasaa, and Assemblyman. Moreover, the survey indicated that 54.5% of farmers adopted the broadcasting method for planting seeds, while only 18% practiced line transplanting with well-defined spacing. Additionally, a majority of transplanting activities occurred when seedlings were at least 4 weeks old, highlighting potential inefficiencies in timing. The study identified several constraints hindering rice production in both lowland and irrigated rice ecosystems across the surveyed districts. These constraints include the prevalence of poor-quality seed varieties, inadequate spacing, suboptimal timing of transplanting, and low soil fertility. Addressing these challenges is imperative for enhancing rice productivity and promoting sustainable agricultural practices in the region.

Increased tree water use with the development of a dense understory layer in a North American hardwood forest

AbstractThe formation of a single species, recalcitrant understory vegetation layer can limit tree regeneration and, in the long term, modify the composition of forests. Few studies have investigated how recalcitrant vegetation influences competition for water resources although the formation of a dense understory is likely to modify the forest water balance. In eastern North American hardwood forests, the development of a dense understory layer of American beech (Fagus grandifolia) has been observed in stands dominated by sugar maple (Acer saccharum), a phenomenon that shares many characteristics associated with recalcitrant vegetation. Given that water availability is generally negatively correlated with stand density, we hypothesized that the formation of a dense understory beech layer increased competition for water resources, thus leading to reduced water use by sugar maple trees in beech‐dominated stands. Using thermal dissipation sensors, we measured sap flux density (Fd) of two sugar maple trees at three beech‐dominated sites and three control sites. During the growing season, Fd of sugar maple trees was significantly larger at beech‐dominated sites compared to control sites, indicating a greater rate of water use by sugar maples in stands with a dense understory beech layer. We provide two hypotheses to explain our results at the tree scale: (i) reduced cover by forest floor vegetation could limit transpiration by this layer, thus allowing increased water availability to supply transpiration by overstory trees, or (ii) increased tree transpiration rate could be a mechanism to satisfy nutrient requirements in beech‐dominated stands often associated with lower soil fertility.

ДИКОПЛОДОВЫЕ ПОРОДЫ НА НАРУШЕННЫХ ЗЕМЛЯХ СЕВЕРНОГО КАВКАЗА

Wild fruit species on disturbed lands grow in degraded areas and have the ability to quickly restore the ecosystem. Restoration of disturbed lands in mountain and piedmont areas plays a big role and is a significant resource in the national economic potential of the region, an important reserve for agricultural production. The article provides an overview of the disturbed lands of the North Caucasus as a result of mining. For the purpose of biological rehabilitation, a classification of technogenic landscapes has been developed. The state of wild fruit and berry plants in disturbed areas has been revealed, which depends on the types of substrate, topography, climate, parts of the slopes and their steepness. Eleven wild fruit species grow naturally in quarries in the study region. Among them, sea buckthorn and dog rose stand out. They tolerate drought well and are resistant to low soil fertility. Cherry plum, common hazel and hawthorn prefer better moisture conditions. The degree of root growth in different parts of the slope has been established, which makes it possible to determine the suitability of soil and hydrological conditions for wild fruit species and to plan appropriate measures. It has been confirmed that the moist parts of the lower slopes are the most favorable for the growth and development of plants. The individuality of the formation of wild fruit and berry plantings according to the exposures at each deposit separately is noted. The prospects of wild fruit breeds capable of producing root shoots are substantiated. It was revealed that the spread of root suckers occurs more intensively on light soils, despite the fact that moisture is better on clay; this is not the main criterion for the spread of suckers. An assortment of wild fruit plants has been developed to create protective plantings in various environmental conditions. Measures are proposed to restore disturbed lands. Key words: WILD FRUIT SPECIES, DISTURBED LANDS, SLOPE, QUARRY, REHABILITATION, ROOT OFFSPRING, ASSORTMENT

Response of tef yield and yield components to nitrogen and phosphorus fertilizers.

The challenge facing Ethiopian farmers are the combination of low soil fertility and reduced agricultural productivity. The study aimed to quantify nitrogen and phosphorus-containing fertilizers for tef production in Sekota and Lasta-Lalibela districts, using four nitrogen and three phosphorus levels from urea and triple super phosphate sources. The Results showed that nitrogen and phosphorus fertilizers significantly affected tef yield and yield components. Application of nitrogen at the rate of 92 kg ha-1 increased tef grain yield by 131.01%, 87.78% and 182.23% in Woleh, Sayda and Lasta Lalibela districts, respectively, compared to control treatment. Similarly, 23 kg ha-1 phosphorus increased tef grain yield by 7.42 and 8.52% in Woleh and Lasta Lalibela, respectively. In Lalibela and Woleh, the application of 92 kg N ha-1 resulted in a maximum net benefits of 2099.6 and 2007 United States Dollar (USD) respectively. Furthermore, in Sayda, the application of 92 kg N ha-1 and 23 kg P2O5 ha-1 yielded a net benefit of 1812.55 USD. The marginal rate of return (MRR) from these applications was 539.6% in Lalibela, 781% in Woleh and 352.44% in Sayda. Therefore, application of 92 N and 23 kg P2O5 ha-1 is appropriate for maximum tef production in Sekota and Lasta districts of Amhara region. Further research and extension services should focus on promoting the adoption of these optimized fertilizer practices among smallholder farmers to maximize the sustainable production of tef.

Combined Effects of Rice Husk Biochar and Organic Manures on Soil Chemical Properties and Greenhouse Gas Emissions from Two Different Paddy Soils

The application of biochar is considered an alternative amendment strategy for improving soil fertility. In this study, we performed pot experiments using soils of low and medium fertility to assess the effects of different combinations of biochar and organic manure on the chemical properties of paddy rice soils and determined the best combination to improve the grain yield without increasing N2O and CH4 emissions. The applied treatments were without biochar (control), the application of rice husk biochar alone (5 and 10 t ha−1), and biochar combined with chicken or cow manure. The results indicated that for both soils, the application of 5 t ha−1 biochar combined with 5 t ha−1 chicken manure increased grain yield by improving soil total nitrogen and soil NH4+-N without increasing cumulative N2O and CH4 emissions. Multiple regression analysis showed that when combined with biochar, chicken manure significantly contributed to a higher grain yield and was negatively associated with cumulative CH4, N2O emissions, and total GWP. Furthermore, regardless of soil type, combined applications of biochar and cow manure promoted significant increases in soil available P. Our findings indicate that the C/N ratio of organic manure influences CH4 fluxes, and soil type was identified as a factor driving greenhouse gas emissions.

Short Term Effect of Vermicompost on Soil Chemical Properties under Maize (Zea mays L.) Field in Northern Ethiopia

Aim: The application of vermicompost (VC) to improve soil chemical properties in area that have low soil fertility status is crucial. Thus, the present study was initiated to determine impact of vermicompost on selected soil physicochemical properties. Study Design: The experiment had 7 treatments arranged in a Randomized Complete Block Design (RCBD) with five replications. Place and Duration of the Study: Hence, a field experiment was carried out in 2018 main cropping season at farmer's field at Adiha village in Kolla Tembien district, Tigray, Ethiopia. Methodology: The treatments were 5 levels of VC (0, 2.5, 5, 7.5 and 10 t ha-1), the recommended rate of N and P (46 N and 46 P2O5 kg ha-1), compost at rate of 10 t ha-1 and control. Surface soil samples were collected before planting and after maize harvesting at a depth of 0-30 cm to analyze selected soil chemical properties such as pH, extractable electric conductivity (ECe), cation exchange capacity (CEC), total nitrogen (TN), available P and exchangeable bases (K, Mg, Ca, and Na). Likewise, vermicompost and compost nutrient contents were also analyzed to know their nutrient composition. Results: Soil analysis results before sowing revealed that most of the soil chemical properties were rated as low. However, vermicompost application significantly (P≤0.05) improved the soil chemical properties. The studied soil chemical properties such as OC (1.33%), TN (0.13%), CEC (17.2 Cmol (+) kg-1), and available P (6 .38 mg kg-1) showed an improvement at VC 10 t ha-1rate as compared to the control which was respectively 0.65%, 0.04%, 7.4 Cmol(+)kg-1 and 2.45 mg kg-1. Conclusion: A significant (P≤0.05) increase in OC, TN and available P was observed with increased vermicompost rate under cultivated land.

Microbial mechanisms of organic matter mineralization induced by straw in biochar-amended paddy soil

Combined straw and straw-derived biochar input is commonly applied by farmland management in low-fertility soils. Although straw return increases soil organic matter (SOM) contents, it also primes SOM mineralization. The mechanisms by which active microorganisms mineralize SOM and the underlying factors remain unclear for such soils. To address these issues, paddy soil was amended with 13C-labeled straw, with and without biochar (BC) or ferrihydrite (Fh), and incubated for 70 days under flooded conditions. Compound-specific 13C analysis of phospholipid fatty acids (13C-PLFAs) allowed us to identify active microbial communities utilizing the 13C-labeled straw and specific groups involved in SOM mineralization. Cumulative SOM mineralization increased by 61% and 27% in soils amended with Straw + BC and Straw + Fh + BC, respectively, compared to that with straw only. The total PLFA content was independent of the straw and biochar input. However, 13C-PLFAs contents increased by 35–82% after biochar addition, reflecting accelerated microbial turnover. Compared to that in soils without biochar addition, those with biochar had an altered microbial community composition-increased amounts of 13C-labeled gram-positive bacteria (13C-Gram +) and fungi, which were the main active microorganisms mineralizing SOM. Microbial reproduction and growth were susceptible to nutrient availability. 13C-Gram + and 13C-fungi increased with Olsen P but decreased with dissolved organic carbon and NO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{NO}}_{3}^{ - }$$\\end{document} contents. In conclusion, biochar acts as an electron shuttle, stimulates iron reduction, and releases organic carbon from soil minerals, which in turn increases SOM mineralization. Gram + and fungi were involved in straw decomposition in response to biochar application and responsible for SOM mineralization.Graphical

IMPACT DES FUMURES ORGANIQUE ET MINERALE SUR LES PARAMETRES AGRONOMIQUES DU MIL (PENNISETUM GLAUCUM (L.) R. BR.) A TARNA, NIGER

Millet, Pennisetum glaucum (L.) R. Br. is the excellent crop adapted to the particular production conditions of the Sahel. However climatic hazards and inherent low soil fertility reduce millet yield. Hence, this study aims to evaluate the impact of organic and mineral fertilizers on agronomic parameters of millet. The trial was conducted at the experimental station of the regional agricultural research center of Tarna (Maradi). The experimental design is a randomized complete block with 12 treatments replicated three times. The plant material used is SOSAT C88. The parameters measured are emergence rate, tillering bolting and millet yield. Results analysis shows that the use of organic and mineral fertilizers significantly affect tillering, bolting and millet yield. The results obtained show that the application of organic and mineral fertilizers improves the agronomic parameters of millet.

Response of maize yield and nitrogen recovery efficiency to nitrogen fertilizer application in field with various soil fertility.

Appropriate nitrogen (N) management system is essential for effective crop productivity and minimizing agricultural pollution. However, the underlying mechanistic understanding of how N fertilizer regulates crop yield via soil properties in soils with different fertilities remains unresolved. Here, we used a field experiment that spanned 3 cropping seasons to evaluate the grain yield (GY), aboveground biomass and N recovery efficiency (NRE) after treatment with five N fertilizer application rates (N0, N75, N112, N150, and N187) in soils with three levels of fertility. Our results indicated that the highest GY across low, moderate, and high fertility soils were 1.5t hm-2 (N150), 4.9t hm-2 (N187), and 5.4t hm-2 (N112), respectively. The highest aboveground biomass and NRE were observed at N150 for all three levels of soil fertility, while only the N uptake by aboveground biomass of low and high fertility soils decreased at N187, confirming that excessive N fertilization results in a further decline in crop N uptake. The relationship between GY, NRE and N fertilizer application rates fit the unary quadratic polynomial model. To achieve a balance between grain production and environmental benefits in N fertilizer, appropriate N fertilizer rates were determined to be 97.5kg hm-2, 140kg hm-2 and 131kg hm-2 for low, moderate and high fertility soils, respectively. Structural equation modeling suggested that GY was significant correlated with soil microbial biomass carbon (SMBC) and N directly in low fertility field, with SMBC directly in moderate fertility field, and via SOC and NO3 -N in high fertility field. Therefore, a soil-based management strategy for N fertilizers could enhance food security while reducing agricultural N fertilizer inputs to mitigate environmental impacts.

Effect of ridging and tie-ridging time on yield and yield component of sorghum in Northern Ethiopia

Soil moisture stress and low soil fertility are the main constraints to sorghum production in the semi-arid region of northern Ethiopia. A field experiment was conducted in Lasta and Sekota Woreda of Amhara Region, eastern Ethiopia, to evaluate the effect of ridge and tie ridge time on the yield and yield component of sorghum (Sorghum bicolor). The experiment consisted of eight treatments of ridging time & time of tie (Tie-ridging at planting, Ridge at planting tying 2 Weeks After Planting, Ridge at planting tying 4 Weeks After Planting, Tie-ridging 3 Weeks After Planting, Ridging 2 Weeks After planting & tying 4 Weeks After Planting, Ridge 3 Weeks After Planting & tying 6 Weeks After Planting, Tie-ridging 6 Weeks After Planting); including Shilshalo as a control farmer practice which was arranged in a randomized complete block design (RCBD) with three replication. The results of the experiment revealed that the timing of ridging and tie ridging had a significant effect on sorghum yield. The results showed that tie ridging at planting time increased sorghum yield by about 37.9% in Sekota compared to the control (farmer practice), and tie ridging three weeks after planting in Lalibela increased sorghum yield by 30.11% compared to the control (farmer practice). The highest yields of 3.642 tons/ha were obtained with tie ridging at planting in Sekota and 1.903 tons/ha with tie ridging three weeks after planting in Lalibela. Therefore, tie ridging and ridging at planting may be appropriate for sorghum production in the Sekota and sorghum growing areas. However, in Lalibela and sorghum growing areas, tie-ridging three weeks after planting may be appropriate for sorghum production.

Spatial distribution of Pb and Zn in soils under native vegetation in Southeast Brazil.

Heavy metals can play an important biological role as micronutrients but also as potentially toxic elements (PTEs). Understanding the natural concentrations of PTEs-Pb and Zn included-in soils allows for the identification and monitoring of contaminated areas and their role in environmental risk assessment. In this study, we aim to determine semi-total or natural and available concentrations of Pb and Zn in topsoils (0-20 cm depth) from 337 samples under native vegetation in the State of Minas Gerais, Brazil. Additionally, we sought to interpret the spatial geochemical variability using geostatistical techniques and quality reference values for these elements in soils were established. The semi-total concentrations were determined by flame and graphite furnace atomic absorption after microwave-assisted nitric acid digestion method. The available concentrations were extracted using the Mehlich-I extractor and determined by atomic absorption spectrometer. Spatial variability was modeled using semivariance estimators: Matheron's classic, Cressie and Hawkins' robust, and Cressie median estimators, the last two being less sensitive to extreme values. This allowed the construction of digital maps through kriging of semi-total Pb and Zn contents using the median estimator, as well as other soil properties by the robust estimator. The dominance of acidic pH and low CEC values reflects highly weathered low-fertility soils. Semi-total Pb contents ranged from 2.1 to 278 mg kg-1 (median: 9.35 mg kg-1) whereas semi-total Zn contents ranged from 2.7 to 495 mg kg-1 (median: 7.7 mg kg-1). The available Pb contents ranged from 0.1 to 6.92 mg kg-1 (median: 0.54 mg kg-1) whereas available Zn contents ranged from 0.1 to 78.2 mg kg-1 (median: 0.32 mg kg-1). The highest Pb and Zn concentrations were observed near Januária, in the northern part of the territory, probably on limestone rocks from the Bambuí group. Finally, the QRVs for Pb and Zn in natural soils were lower than their background values from other Brazilian region and below the prevention values suggested by Brazilian environmental regulations.

Soil fertility impact on recruitment and diversity of the soil microbiome in sub-humid tropical pastures in Northeastern Brazil

Soil fertility is key point to pastures systems and drives the microbial communities and their functionality. Therefore, an understanding of the interaction between soil fertility and microbial communities can increase our ability to manage pasturelands and maintain their soil functioning and productivity. This study probed the influence of soil fertility on microbial communities in tropical pastures in Brazil. Soil samples, gathered from the top 20 cm of twelve distinct areas with diverse fertility levels, were analyzed via 16S rRNA sequencing. The soils were subsequently classified into two categories, namely high fertility (HF) and low fertility (LF), using the K-Means clustering. The random forest analysis revealed that high fertility (HF) soils had more bacterial diversity, predominantly Proteobacteria, Nitrospira, Chloroflexi, and Bacteroidetes, while Acidobacteria increased in low fertility (LF) soils. High fertility (HF) soils exhibited more complex network interactions and an enrichment of nitrogen-cycling bacterial groups. Additionally, functional annotation based on 16S rRNA varied between clusters. Microbial groups in HF soil demonstrated enhanced functions such as nitrate reduction, aerobic ammonia oxidation, and aromatic compound degradation. In contrast, in the LF soil, the predominant processes were ureolysis, cellulolysis, methanol oxidation, and methanotrophy. Our findings expand our knowledge about how soil fertility drives bacterial communities in pastures.

From individual leaves to forest stands: importance of niche, distance decay, and stochasticity vary by ecosystem type and functional group for fungal community composition.

Community assembly is influenced by environmental niche processes as well as stochastic processes that can be spatially dependent (e.g. dispersal limitation) or independent (e.g. priority effects). Here, we sampled senesced tree leaves as unit habitats to investigate fungal community assembly at two spatial scales: (i) small neighborhoods of overlapping leaves from differing tree species and (ii) forest stands of differing ecosystem types. Among forest stands, ecosystem type explained the most variation in community composition. Among adjacent leaves within stands, variability in fungal composition was surprisingly high. Leaf type was more important in stands with high soil fertility and dominated by differing tree mycorrhizal types (sugar maple vs. basswood or red oak), whereas distance decay was more important in oak-dominated forest stands with low soil fertility. Abundance of functional groups was explained by environmental factors, but predictors of taxonomic composition within differing functional groups were highly variable. These results suggest that fungal community assembly processes are clearest for functional group abundances and large spatial scales. Understanding fungal community assembly at smaller spatial scales will benefit from further study focusing on differences in drivers for different ecosystems and functional groups, as well as the importance of spatially independent factors such as priority effects.

Effects of Inorganic Phosphorus and Organic Fertilizer on Growth and Yield of Common Bean (Phaseolus Vulgaris L.) under Kabul Conditions

In Afghanistan, the main reasons for low crop yields are low soil fertility. Growing human populations has resulted in shrinking land areas and decreased soil fertility. Also, the overuse of chemical fertilizers is considered to be the main cause of soil characteristics deterioration, such as soil fertility, soil biology, and soil physical properties. On the other hand, no research has been done to find the ideal phosphorus and organic (ORGOFERT) fertilizer rate for improving common bean production in Afghanistan. Thus, it is pertinent to determine the optimum phosphorus and organic fertilizer dose for common bean cultivation in Afghanistan, where this crop is grown expensively. In 2020, a field trial took place at the agriculture faculty research farm of Kabul University during the growing season. The trial utilized a randomized complete block design (RCBD) with three replications. Each plot measured 200cm x 300cm, with plants spaced 40 cm apart in rows and 20 cm apart within rows. Different amounts of phosphorus and organic fertilizer were applied in the experiment. The results indicated that employing 50 kg of ORGOFERT and 80 kg of P2O5 fertilizers per hectare led to enhanced growth parameters such as plant height, number of branches per plant, and number of green leaves per plant, as well as improved yield attributes including the number of pods per plant, number of grains per pod, 100-grain weight, and total grain yield per hectare. The ideal amount of phosphorous and ORGOFERT fertilizer to improve the growth and production of common beans under field conditions might be the rate of 80kg P2O5 + 50 kg ORGOFERT fertilizer ha-1 under Kabul's agro-ecological conditions.

Institutionalization of integrated pest management in the food estate development area, Sungai Mandau Subdistrict, Siak Regency, Riau

The food estate program aims to enhance national food production, regional development, food security, and the welfare of farmers. Sungai Mandau, a peatland area in Siak Regency, was opened in 2010 as a food estate for rice cultivation to meet the rice demand in Riau Province. However, peatland development for agriculture faces challenges such as low soil fertility, acidic soil pH, and nutrient deficiencies. This research aims to study the agronomic factors, land suitability, pest management, and agricultural institutions in the context of food estate development in Sungai Mandau. This study starts from August 2022 to April 2023. The method was in-depth interviews with fifty farmers to capture the condition of the Sungai Mandau food estate. Additionally, field observations were conducted on land, soil conditions, pests and diseases. The land condition of the Sungai Mandau food estate falls into suitability class S3 (the lowest suitability) for rice cultivation. Farmers' pest management practices are far from the Integrated Pest Management (IPM) concept. The cultivation practices do not fully support IPM and are not in line with the land conditions. The lack of farmer knowledge is attributed to the ineffective roles of field agricultural extension officer (FAEO) and agriculture technopark (ATP), who should play a significant and close role with the farmers. Information dissemination at the cooperative and farmer group levels has not been effective for a long time. Non-Governmental Organizations (NGOs) play a role in institutionalizing IPM, and this institutionalization can occur when all institutions and stakeholders actively participate.