Low Soil Fertility Conditions Research Articles

Productivity of Açai Euterpe Precatoria and Production System Management Recommendations in the South Of The Amazonas

Objective: To investigate the productivity of the Amazon açaí Euterpe precatoria Mart in order to support recommendations for adapting management to increase productivity in the production system in southern Amazonas. Theoretical Framework: The demand for açaí justifies its domestication to increase productivity in addition to extractive production. In this context, difficulties arise due to the lack of knowledge about managing the species, which is required along with its domestication. Thus, knowledge that supports the supply of soil and nutritional conditions is required for E. precatoria, which is still little studied in terms of management. Method: The productivity assessment was carried out in an experiment whose ages of açaí groves planted side by side, 8, 9, 10 and 12 years old, constituted treatments. For each açaí grove age, randomized by the producer in the planning, 4 experimental plots were designed containing 3 trees spaced 3.0 m x 3.0 m, with 4 replications, totaling 16 experimental plots in randomized blocks. Results and Discussion: The results indicate the need to manage soil fertility to increase the productivity of açaí groves, which are obtained in conditions of low soil fertility, even for the 12-year-old açaí grove, selected as the most productive. Research Implications: This study presents practical and theoretical implications for the açaí palm in Amazonas, whose management is still in its infancy. It identifies low productivity of açaí groves and the need to insert nutrients not only through alternative practices with low economic and environmental impact. Originality/Value: This study contributes to the basis of future studies on the agricultural management of the Amazon açaí tree as a cultivable species.

Understanding the interactions of genotype with environment and management (G×E×M) to maize productivity in Conservation Agriculture systems of Malawi.

Climatic variability and soil fertility decline present a fundamental challenge for smallholder farmers to determine the optimum management practices in the production of maize. Optimizing genotype (G) and management (M) of maize under different environmental conditions (E) and their interactions are essential for enhancing maize productivity in the smallholder sector of Malawi where maize is the main staple food. Here, we evaluated over seven seasons, the performance of four commercial maize genotypes [including hybrids and one open pollinated variety (OPV)] managed under different Conservation Agriculture (CA) and conventional practices (CP) across on-farm communities of central and southern Malawi. Our results revealed significant G×E and E×M interactions and showed that hybrids such as DKC 80-53 and PAN 53 outyielded the other hybrid and the OPV in most of the environments while the OPV ZM523 had greater yields in environments with above-average rainfall and shorter in-season dry spells. These environments received a maximum of 1250 mm to 1500 mm of rainfall and yet the long-term averages were 855 mm and 1248 mm, respectively. Despite yielding lower, the OPV ZM523 also exhibited higher yield stability across environments compared to the hybrid MH 30, possibly due to its resilience to drought, heat stress, and low soil fertility conditions which are often prevalent in the target communities. Conservation Agriculture-based practices outyielded CP across the genotypes and environments. However, amongst the CA-based systems, intercropping of maize with pigeonpea [Cajanus cajan (L.) Millsp] and cowpea (Vigna unguiculata Walp.) performed less than monocropping maize and then rotating it with a legume probably due to competition for moisture between the main and the companion crops in the intercrop. The key findings of this study suggest the need to optimize varietal and management options for particular environments to maximize maize productivity in Malawi. This means that smallholder farmers in Malawi should adopt hybrids and CA-based systems for enhanced yields but could also consider OPVs where the climate is highly variable. Further rigorous analysis that includes more abiotic stress factors is recommended for a better understanding of yield response.

Use of <i>Hermetia illucens</i> hermicompost in the technology of growing legume microgreens

Relevance. The work describes the prospect of using black soldier fly zoohumus as an organic fertilizer to activate the growth of microgreens of non-traditional legume species, including small-seeded ones, and the prospects of reducing the dose of mineral fertilizers.Methods. An experiment was carried out with a comparative study of changes in the morphometric and chemical parameters of plant growth at the full recommended dose of mineral fertilizers, and at 25% of their use, but with the addition of 1% liquid extract of zoohumus, also enriched with essential elements. The duration of the experiment was 21 days. The plants were grown in a closed grow tent, with intensive light culture and control of the internal microclimate of the working area.Results. Among the six studied non-traditional legume species grown for microgreens, the most responsive to combined treatment with an organomineral complex was Onobrychis viciifolia. Trifolium rubens showed the worst result in terms of biomass. Analysis of changes in the profile distribution of essential elements in the resulting green biomass, carried out using inductively coupled plasma atomic emission spectroscopy (ICP-AES), revealed iron and zinc ions as potential targets associated with yield shortfalls in juvenile shoots. Since in global food systems these microelements are the most common nutrients noted for the manifestation of “hidden hunger”, especially among children under 5 years of age and women of childbearing age, when creating a nutritional biocomposition based on black soldier fly zoohumus for growing non-traditional types of legumes, further the emphasis should be on them. No significant differences were found in the number of macroelements.Results. The results of the study confirmed the high efficiency of using humic fertilizers in conditions of low soil fertility and revealed the selective sensitivity of vegetable crops to humic preparations of various origins.

Assessment of the effect of organic fertilizers on growth and biochemical parameters of <i>Lepidium sativum</i> and <i>Raphanus sativus</i>

Relevance. The article presents the results of studying the effect of organic fertilizers of various origins on vegetable crops of radish and watercress. The relevance of the study is related to the need to find the most effective preparations based on humic acids from a wide list offered for use in crop production.Methods. The research was carried out in a model experiment in 2022–2023 with humic fertilizers of geological (“Humate K”) and biological (“AgroVerm” and “Humate K”) origin. The study of the effect of meliorants was carried out on vegetable crops: radish of the Heat variety and watercress of the Moscow Greenhouse variety. The data obtained allow us to conclude that the application of organic fertilizers significantly increases germination, stimulates the growth and development of crops. The effect of humic preparations significantly increased growth indicators and the content of photosynthetic pigments in the green mass of plants with control. For the watercress culture, the highest yield values (1.46 kg /m2) were noted against the background of the introduction of the drug “Humate K”, and for radish, the maximum yield value (2.8 kg/ m2) was observed in the variant of using the effluent Samorod.Results. The results of the study confirmed the high efficiency of using humic fertilizers in conditions of low soil fertility and revealed the selective sensitivity of vegetable crops to humic preparations of various origins.

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.

The effect of root cutting on the availability of organic carbon stock in oil palm plants (elaeis guneensis jacq)

Palm oil (Elaeis guenesis jacq) is an important commodity in Indonesia. Assessments of the underlying causes of yield gaps in oil palm production systems worldwide are lacking in exploring existing knowledge about oil palm productivity from a crop physiological perspective. Modifying the roots of oil palm plants through root cutting can affect the availability of carbon stocks in the soil because roots are one of the sources of organic carbon input into the soil. The purpose of the study was to analyses the effect of cutting the roots of oil palm plants on the availability of carbon stocks and soil fertility for these crops. The land where the study took place had a relatively low soil fertility status, there were several parameters observed showing low availability status in the soil. The low content of nutrients in the soil causes limited soil in providing nutrients to support plant growth.

Yield Response of Chick Pea (Cicer arietinum L.) Varieties to NPS Fertilizer

Low soil fertility status and reduced biological nitrogen fixation are some of the major constraints in limiting chickpea yield. Thus, an experiment was conducted with the objective of assessing the effect of blended NPS fertilizer rates on the yield and yield components and economic advantages of chickpea varieties. The experiment was done using randomized complete block design with five NPS rates (0, 50, 75, 100 and 125 kg ha-1) and three chick pea varieties (Arerty, Shasho and Teketay) in three replications. The result showed that the main effect of variety had significant effect on days to 50% flowering, days to maturity, plant height, population at harvest, number of secondary branches, number of pods per plant, number of seed per pod, 100 seed weight, biological yield, grain yield and harvest index. Application of NPS significantly influenced number of pod per plant, biological yield, grain yield and harvest index. In addition, the pooled effect of the two factors showed highly significant differences on days to 50% germination, population at emergence and primary plant branches. Hence, Arerty variety showed an increased yield throughout the applied rates and attained its highest yield (3166.70 kg) at 125 kg ha-1 NPS applied along with the highest profit gaining. Shasho variety also showed a positive yield response at all treated plots as compared to the control; but attained maximum yield (2861 kg ha-1) at 100 kg ha-1 NPS applied. However, maximum profit was attained at rate of 75 kg ha-1 NPS. Teketay variety attained highest yield (3138.70 kg ha-1) at 100 kg ha-1 NPS applied; however its highest benefit to cost ratio (1.73) with highest economic benefit was reached at 50 kg ha-1 NPS applied. Thus, based on results obtained from this study, it can be concluded that using 100kg, 75kg and 50kg of NPS fertilizer ha-1 application for Arerty, Shasho, and Teketay varieties respectively improved productivity of chickpea with economically significant amount at the vicinity of the research area.

Source–Sink Balance Optimization Depends on Soil Nitrogen Condition So as to Increase Rice Yield and N Use Efficiency

Genetic improvement has been devoted to increasing rice yield by increasing the spikelet number per panicle and the spikelet/leaf ratio. As a result, indica-japonica hybrid rice “Yongyou” varieties with large panicles and superhigh yield potential have been developed. These varieties exhibit significantly higher grain yield and nitrogen use efficiency for grain (NUEg) under moderate and high N supply conditions due to their large sink size, but their yield performance remains obscure under low N input and low soil fertility conditions. In the present study, we investigated four varieties including Yongyou2640 (YY2640, large-panicle india-japonica hybrid variety), Yangliangyou6 (YLY6, two-line indica hybrid variety), Quanyou6 (QY6, three-line indica hybrid variety), and Huanghuazhan (HHZ, indica inbred variety) under two low soil fertility treatments [LF (removing half of soil depth) and CK] and two N fertilizer rates (0 and 100 kg N ha−1) in Central China. The results showed that the grain yield of YY2640 was more responsive to fertility than that of other varieties, which was 19.4–42.3% higher than that of the other three varieties under CK N100 treatment, but it was 14.5–19.4% lower than that of YLY6 and QY6 under LF N0 and LF N100. A higher spikelet/leaf ratio resulted in more biomass and N partition to panicles rather than to leaves under LF N0 and N100. Slightly more post-flowering dry matter obtained from higher leaf N content and crop growth rate failed to compensate for the adverse effects of reduced pre-flowering dry matter accumulation and stem-to-grain translocation during grain filling. This led to the lower NUEg of YY2640 than YLY6 and QY6 under low soil fertility conditions. Based on these findings, the present study suggested that the source–sink relationship of the super hybrid varieties should be optimized according to the soil N supply condition.

EFFECT OF VERMICOMPOST-TEA AND PLANT EXTRACTS ON GROWTH, PHYSIOLOGICAL, AND BIOCHEMICAL TRAITS OF LETTUCE (LACTUCA SATIVA L.)

The vermicompost and exogenous plant extracts as a foliar application can provide as an alternative means to enhance the growth and yield of leafy vegetable crops under low-fertility soil conditions. The objectives of the recent study sought to characterize the effect of vermicompost tea in combining some natural plant extracts to enhance the growth and yield of the lettuce plant. A study on lettuce (Lactuca sativa L.) took place during two successive seasons, in 2018–2019 and 2019–2020, using foliar spray— vermicompost-tea rates in combination with rosemary leaf extract (RLE) and eucalyptus buds extract (EBE). It sought to determine the effects on growth, yield, and some physiological and biochemical traits of lettuce (cv. ‘Dark Green’) grown on sandy soil with drip irrigation. The experiment employed the split-plot design, with four rates of vermicompost tea (0%, 5%, 10%, and 20%) as main plots and three plant extract levels (without, RLE, and EBE) as subplots. The vermicompost tea and plant extracts increased the growth characteristics, photochemical activity, photosynthetic pigments, relative water content, membrane stability index, excised leaf water retention, vitamins C and E, and total soluble solids in lettuce plants compared with the untreated control plots. The interaction and combined application of vermicompost tea (20%) and RLE proved most effective in enhancing the growth and yield traits and physio-biochemical properties in lettuce. Therefore, the integrative application of vermicompost tea (20%) with RLE comes highly recommended for growing lettuce in sandy soil conditions.

Identification of soil fertility status of subak rice fields based on soil chemical properties in Denpasar city, Bali, Indonesia

Soil functions as a storehouse of nutrients that are needed by plants for growth and production. Decreased soil fertility will cause a decrease in productivity due to reduced nutrients in the soil. To determine the state of nutrients, it is necessary to evaluate the status of soil fertility. This study was carried out in the Subak rice fields in Denpasar City, Bali Province, Indonesia. Denpasar City, is the capital of Bali Province which continues to grow, relying on the rice production from its rice fields. The main objective of the study was to evaluate the fertility status of soils in Subak rice fields in Denpasar City based soil chemical properties and to map their fertility status using Geographic Information System (GIS). The approach for this study included surveying and soil sample analysis. The parameters observed were soil chemical properties including: CEC, Base Saturation, C-Organic, P2O5, K2O and pH. The study delineated three categories of soil fertility status, namely high, moderate and low. The total area with high soil fertility was 1312.76 ha (63.77 %), while for the medium and low, the respective total areas were 560.83 ha (27.24 %) and 184.89 ha (8.98 %). The Subak condition with low soil fertility has deficiency in soil organic Carbon (C) content and low total Phosphorus (P). Recommendations for managing low soil fertility status are addition of organic matter and P fertilizer of 100 kgha-1. The spatial distribution of soil fertility status in Denpasar City was mapped using GIS. The distribution of fertility status in these rice fields shows that the majority of the fields classified as high fertility are located in East and South Denpasar. The different fertilization regimes followed between the Subaks were the cause of the observed different soil nutrient statuses. Therefore, it is necessary to give the same treatment in order to maintain soil fertility. Soil fertility and maintenance of agricultural land productivity were factors that supported food security in Denpasar City. Key words: Subak, Rice fields, Soil Fertility, Chemical Properties, Geographic Information System

Biomass production and nutrient use efficiency in white Guinea yam (Dioscorea rotundata Poir.) genotypes grown under contrasting soil mineral nutrient availability.

Yam (Dioscorea spp.) is of great importance to food security, especially in West Africa. However, the loss of soil fertility due to dwindling fallow lands with indigenous nutrient supply poses a challenge for yam cultivation. This study aimed to determine shoot and tuber biomass and nutrient use efficiency of white Guinea yam (Dioscorea rotundata) grown under low- and high-NPK conditions. Six white Guinea yam genotypes were used in field experiments conducted at Ibadan, Nigeria. Experiments were conducted with low soil NPK conditions with zero fertilizer input and high soil NPK conditions with mineral fertilizer input. Differences in response to soil NPK conditions, nutrient uptake, and nutrient use efficiency (apparent nutrient recovery efficiency) were observed among the tested genotypes. The genotypes TDr1499 and TDr1649, with high soil fertility susceptibility index (SFSI>1) and an increase in shoot and tuber biomass with fertilizer input, were recognized as susceptible to soil NPK conditions. There was a marked difference in apparent nutrient recovery efficiency; however, there was no varietal difference in physiological efficiency. Differences in apparent nutrient recovery efficiency among genotypes affected the fertilizer response (or susceptibility to soil NPK conditions) and the nutrient uptake. In contrast, the genotype TDr2029, with SFSI<1 and low reduction in shoot and tuber production between non-F and +F conditions, was recognized as a less susceptible genotype to soil NPK status. It was revealed that NPK fertilization did not reduce tuber dry matter content, regardless of genotype differences in susceptibility to soil NPK conditions. Hence, this could be helpful to farmers because it implies that yield can be increased without reducing tuber quality through a balanced application of soil nutrients. Our results highlight genotypic variation in sensitivity to the soil NPK availability, nutrient uptake, and nutrient use efficiency white Guinea yam. Differences in susceptibility to soil NPK conditions could be due to the genotypic variations in nutrient recovery efficiency white Guinea yam. Our findings could contribute to breeding programs for the development of improved white Guinea yam varieties that enhance productivity in low soil fertility conditions with low and high-input farming systems.

Co-Application of Biochar Compost and Inorganic Nitrogen Fertilizer Affects the Growth and Nitrogen Uptake by Lowland Rice in Northern Ghana

Inherent low soil fertility status limits productivity of rice in the lowland ecologies in Northern Ghana. Combining organic and inorganic nitrogen fertilizers could help to maintain the fertility of lowland soils for rice production. A screen house pot experiment was carried out to investigate the combined effect of biochar compost and inorganic nitrogen fertilizer on the nitrogen uptake and agronomic performance of rice plants grown on an eutric gleysol lowland soil. Inorganic nitrogen fertilizer alone and its combinations with different types of biochar compost (based on the proportions of biochar and compost) were used as treatment. A control (unamended soil) was also included. The incorporation of biochar compost and inorganic nitrogen fertilizer improved the growth parameters and yield components of rice plants. The combination of biochar compost and inorganic nitrogen fertilizer was also found to improve nitrogen uptake in rice plants. This practice could be the most likely viable option for alleviating lowland soil fertility issues and increasing rice productivity in Northern Ghana.

Quantifying nutrient stoichiometry and radiation use efficiency of two maize cultivars under various water and fertilizer management practices in northwest China

Precise nutrient diagnosis is the basis of accurate simulation of maize (Zea mays L.) grain yield and high-efficient utilization of resources under the changing climate. However, the combined effects of supplementary irrigation and fertilizer application on plant stoichiometry of various maize cultivars in water-limited and nutrient-deficient regions are still poorly understood. A three consecutive year field experiment (2015−2017) was conducted on two maize cultivars (QL14 and ZD958) in northwest China, with two irrigation treatments (RF: rain-fed and DI: drip irrigation) and two fertilization treatments (F0: no fertilization and F1: local fertilization practice). The results showed that the radiation use efficiency for biomass yield of QL14 with fertilization under drip irrigation was increased by 7.39% than that of ZD958. DI (70.19 kg kg−1) and ZD958 (68.55 kg kg−1) obtained significantly higher physiological efficiency of nitrogen fertilizer than RF (59.52 kg kg−1) and QL14 (61.17 kg kg−1), respectively. Both plant and grain N:P ratios under F1 were higher than those under F0. QL14 had significantly higher grain N:P ratio (4.64) than ZD958 (4.26) under DIF1. Grain yield was increased obviously when grain N:P ratio and plant N:K stoichiometry were greater than 4.0 and 1.2, respectively. The newly released maize cultivar (QL14) was highly recommended as forage and cereal crops, since QL14 obtained significantly higher leaf and stem dry matter even under severe drought and low soil fertility conditions. Our study provides an opportunity to achieve high-yielding maize systems in northwest China and maybe other regions with similar environments, and the data will help inform policies and strategic plans for the effective use of water and fertilizer resources.

Spatial Distribution of Landslide Potential and Soil Fertility: A Case Study in Baturiti District, Tabanan, Bali, Indonesia

Baturiti District is an area with history of high landslides yearly. Steep topography and steep slopes are some causes of landslides in the area. Minimal information regarding the potential for landslides can result in many victims and large losses if the disaster occurs in Baturiti District, Tabanan Regency, Bali Province-Indonesia. This study is crucial because of the urgency of the two factors that trigger land degradation. There has been no research on landslides on agricultural land and their relationship with soil fertility. Identical soil fertility is in loose soil, while loose soil is relatively easy to experience soil movement and cause landslides. This simple statement needs to be scientifically proven implemented in this research. Such conditions become a novelty in this scientific article. The purpose of this study was to identify the potential for landslides, the impact on agricultural land, and its correlation to the fertility of agricultural land. The method used is a survey method, soil analysis in the laboratory, and scoring with several landslide parameters, namely land use, slope, rainfall, landform, and geological structure. Soil fertility status analysis refers to the Soil Research Center (PPT) 1995 with 5 important parameters determining soil fertility status: CEC, Base Saturation, C-Organic, P-Total, and K-Total. Spatial data parameters were analyzed using a Geographic Information System. The results showed that the highest landslide susceptibility area was horticultural agricultural land (2,369.11 ha), applied to steep to very steep slopes. Another cause is the landform factor of the volcano's upper slopes, which has a soil-forming fraction dominated by coarse materials and high rainfall. Baturiti sub-district has low, medium, and high soil fertility status. The correlation between the vulnerability to landslides and soil fertility by (R2= 0.526). Such conditions indicate that areas with high landslide susceptibility have low soil fertility status with moderate correlation.

Cluster Based Pre-scaling Up of Soil Test Fertilizer Recommendation Rate for Maize in Selected Districts of Buno Bedele Zone, Southwestern Ethiopia

Ethiopia is grappling with overwhelming challenges to produce more food for a fast-growing population due to fragmented land with low soil fertility status owned by poor smallholder farmers who are unlikely to afford adequate input use. Given this, Bedele Agricultural Research Center with the support of AGP-II conducted; cluster based pre scaling up of soil test fertilizer recommendation rate for maize in selected districts of Buno Bedele zone, Southwester Ethiopia with the objectives of popularizing soil test fertilizer recommendation rate for maize through enhancing farmers’ knowledge and skill and strengthening stakeholders’ linkage in the study areas during 2019 cropping season. Bedele and Chora districts were selected purposively for being maize production potential in the zone and the conducted soil test calibration studies in which two clusters having 52 farmers (45 male and 7 female) were established in collaboration with different level agricultural stakeholders for the sustainability of technology transfer. The total land size used for cluster approach was 15 hectare in which the two maize varieties Shone and BH661 were planted with the site specific soil test based fertilizer application. For technology transfer; training and field day consisting 283 stakeholders (253 male and 30 female) were held. In general, the attained yield of Shone variety in Bedele was 7.3 tons ha^-1, whereas BH661 in Chora district was 5.2 tons ha^-1 that exceeds the attained average national maize yield 3.7 tons ha^-1 in 2019 cropping season. Therefore, scaling-up of the soil test fertilizer recommendation rate for maize should be carried out in the study areas and similar maize potential agro-ecological zones with strong stakeholders’ participation.

Stem portion and number of stakes influence on growth and yield of cassava variety in the South East, Nigeria

Investigations were conducted to study the effect of stem portion and number of stakes per stand on crop establishment, growth and yield of cassava variety NR 8082 in Umudike Southeastern Nigeria during the 2016/17 and 2017/18 cropping seasons. In each year, the experiment was laid out as a 3 × 3 factorial, in randomized complete block design with three replications. Treatments consisted of three stem portions of different physiological ages (top, middle and basal) and three numbers of stakes per stand (1, 2 and 3). The middle and basal stem portions significantly increased percent establishment, plant height and leaf area index at 3 months after planting (MAP) but had no effect on number of storage roots per plant. The best stem portion for storage root yield was, however, the top portion which produced the highest yield on average. Number of stakes per stand did not significantly affect stem girth, number of nodes per plant and leaf area index, but the use of 1 stake per stand increased number of storage roots per plant, root weight and storage oot yield in 2017/2018 cropping season. Number of stakes per stand did not significantly influence storage root yield across the two seasons of evaluation. Interactions between stem portion and number of stakes per stand did not significantly affect storage root yield of NR 8082 high cassava variety in both cropping seasons. Based on the findings, the use of 1 stake per stand is recommended for high root yields of NR 8082 cassava variety under conditions of low soil fertility in Umudike, South East Nigeria. Although the top portion enhanced root yield, farmers could use any of the stem portions, since the middle and basal parts gave satisfactory yields and had better establishment than the former.

Influence of nitrogen supply on gas exchange, chlorophyll fluorescence and grain yield of breeding lines of common bean evaluated in the Amazon region of Colombia

The common bean (Phaseolus vulgaris L.) is a food crop that provides fiber, vitamins and carbohydrates and it is produced by smallholders in developing countries under nitrogen (N)-depleted and low-fertility soil conditions. Soil acidity and the associated aluminum toxic and phosphorus deficient conditions are known to reduce symbiotic N-fixing ability of common bean. Breeding lines of common bean have been developed to adapt to acid-soil and high-temperature conditions in the Amazon region but the response of these lines to N application was not determined. The present study was conducted with an objective to identify genotypic differences among ten common bean breeding lines (4 Andean, 5 Mesoamerican, 1 interspecific) in their physiological characteristics (gas exchange, chlorophyll fluorescence and photosynthetic efficiency) and their contribution to superior agronomic performance under three different levels of N (0, 60 and 120 kg N ha−1; N0, N60 and N120) supply. We tested the hypothesis that common bean genotypes that combine greater capacity to assimilate carbon with improved ability to mobilize photosynthates to developing pods and seeds could enhance their agronomic performance at different levels of N supply under high-temperature and acid soil-stress conditions in the field. A randomized complete block design with factorial arrangement (3 levels of N × 10 genotypes) in three replications was used for the study. Measurements included photosynthetic gas exchange characteristics (light and CO2-saturated photosynthesis), chlorophyll fluorescence, viability of pollen, leaf N concentration, photosynthetic N use efficiency and grain yield. The increase in supply of N had a significant effect on grain yield and on different photosynthetic characteristics. Results showed that lines with indeterminate growth habit responded better to increase in N supply through their physiological response in improving grain yield. Among the genotypes evaluated, two lines (BFS 10 and SEF 10) were outstanding in their agronomic performance due to greater photosynthetic capacity combined with greater ability to mobilize photosynthates to grain with increase in N supply. These two lines can serve as parents for further improvement in resource use efficiency and multiple-stress resistance of common bean in the tropics.

Use of dexcel map method for mapping of soil fertility status in Itagi village of Ranebennur Taluk, Karnataka

It is possible to prepare soil fertility maps by use of MS office (word / Excel / power point) using village land map with survey numbers in excel sheet. The village Itagi is a part of Ranebennur taluk, Karntaka, India which has major soil types black clay soil and red sandy loam soil. Problem cause analysis indicated the low soil fertility status and unscientific use of fertilizers as the reasons for low crop yields. In 86 random locations (on selected survey numbers) soils are sampled, labeled and processed. Samples are analyzed for soil pH, electrical conductivity (EC), organic carbon, macro nutrients and micro nutrients. The status of soil for each property is classified into three classes. Looking to each survey number on the excel sheet, the polygons are filled with colours for respective classes (low, medium and high). The results revealed that 69 per cent of samples belong to alkaline pH and oil salinity is medium in the area. Available nitrogen and phosphorous are low (59 % and 48 %) and available potash is medium (70 %). Organic C belongs to medium to low category. B belongs to low category, while majority of the soils have low status of other micronutrients except Cu. The DEXCEL maps prepared for pH, Av. NPK and organic C indicate the status of soil properties in the village land on respective survey numbers. Which side of the village, the particular soil parameter belongs to low category can be observed and suitable measure can be adopted for the management.

Effect of Integrated Application of Compost and NPS Fertilizer on Selected Soil Physicochemical Properties and Yield of Barley (&amp;lt;i&amp;gt;Hordeum vulgare&amp;lt;/i&amp;gt; L.) at Welmera, Ethiopia

Soil nutrient depletion under losing of soil organic matter content as a result of continuous cultivation and low input are among the major problems that constrain the sustainable productivity of yield of barley at Welmera district. Integrated application of compost and NPS fertilizers can be used to resolve this condition of soil. In this context, a study was conducted in 2019/2020 to determine the effect of combined use of compost and NPS blended fertilizer on soil physicochemical properties and yield of barley at Welmera district. In order to achieve this objective, field experiment was laid out in a randomized complete block design in a factorial arrangement and replicated three times. The results of this study showed that bulk density and total porosity of study area before planting were in acceptable range for barley crop production. The low content of soil organic carbon, total nitrogen, available phosphorus and available sulfur made the fertility status of the soils low. To improve this condition of soil conventional compost and NPS fertilizer were applied to study area soil and combined application of compost at (8 t ha^-1) and mineral NPS fertilizer at (150 kg ha^-1) gave yield of 5.96 t ha^-1. Therefore, based on the result of this study it can be concluded that low soil fertility status, which requires an urgent attention, is one of the major factors hampering the production and productivity of food barley at study area. However, the potential barley productivity of study area soil has not yet been exploited. Therefore, solving the soil fertility problems of the soils of study area through integrated application of compost and NPS fertilizer could be one option to reduce the yield gap seen between smallholder farmers and experimental fields. Hence, the current study recommends that in order to maintain soil fertility and sustain barley crop production combined application of compost at 8 t ha^-1 and NPS fertilizer at 150 kg ha^-1 can be the best alternative integrated soil fertility management option in place of the sole application of inorganic fertilizers for barley production at this area tentatively. Nevertheless, further studies at different locations for more than one cropping seasons should be considered to provide more conclusive recommendation for sustainable food barley production.

Effect of rooting media and number of nodes on growth and leaf yield of chaya (Cnidoscolus aconitifolius McVaugh) at Dire Dawa, Eastern Ethiopia

Chaya known as spinach tree, rich in vitamins and minerals, can grow under drought, low soil fertility conditions and tolerant to insect pest and could be used to tackle malnutrition problem in eas...