Declining Soil Fertility Research Articles

The Integration Hydroponic Aquaculture Systems For Optimizing Catfish Growth Management with Arduino

Modern agriculture faces significant challenges such as limited land and declining soil fertility. The integration of hydroponic systems with aquaculture, particularly catfish farming, offers an innovative solution to enhance agricultural efficiency and productivity. This study explores the integration of hydroponic systems with aquaculture for the simultaneous cultivation of plants and catfish in a controlled environment. The research utilizes Arduino technology for monitoring temperature, pH, and water turbidity, which are essential for the health of fish and plants. The research method used is Research and Development (R&D), involving the following steps: (1) Identifying potential problems, (2) Data collection, (3) Product design, (4) Design validation, (5) Design revision, and (6) Product testing. The results indicate that integrating hydroponic systems with Arduino technology improves the efficiency of monitoring and managing the cultivation environment, positively impacting plant and catfish growth. The implementation of this system shows an increase in plant nutrient content and better fish health. And then, this research significantly contributes to the development of sustainable agriculture and global food security through the adoption of innovative technology.

Прогноз развития процессов деградации на эрозионно опасных склонах черноземов обыкновенных Ростовской области

The decline in soil fertility in recent decades has led to a number of problems in agriculture. The spread of degradation processes forces the use of modern methods of modeling and forecasting erosion. The purpose of this work was to make a long-term forecast of the degradation processes of ordinary chernozems on sloping lands in crop rotations of various designs and using various agricultural technologies using automated neural networks. The research was conducted in a multifactorial long-term experiment, which is located on the slope of the Bolshoy Log beam, in 1990-2022. The experience was laid down in 1986 in the system of contour and landscape organization of the slope area with a steepness of up to 3.5-4°. In the experiment, crop rotations with a different ratio of the proportion of pure steam and perennial grasses in the structure of crops, as well as two tillage systems, were studied. As a result of the research, a forecast was made for a hundred years ahead using automated neural networks, which revealed a general trend of attenuation of erosion processes on slopes, but with varying degrees of intensity, both in crop rotations of various designs and when using various agricultural technologies for cultivating crops. Cultivation of crops in crop rotations with a different proportion from 20 to 40 % of perennial grasses in the structure of sown areas reduces the runoff of meltwater and stormwater by 22.9-24.9 %, washing away the soil by 26.4-28.6 %, and in some cases completely, under exist-ing conditions. The use of soil protection treatment will reduce the runoff of meltwater and stormwater by 39.2-72.0 %, and flushing by 41.5 %.

Sorption of ciprofloxacin and enrofloxacin on alkaline cropland soil in semiarid regions: Roles of pH, ionic strength, and ion type

Animals manure and chemical fertilizers are widely applied to agricultural soils to mitigate soil fertility decline resulting from intensive farming practices. However, the use of antibiotics such as ciprofloxacin (CIP) and enrofloxacin (ENR) in these manures introduces certain environmental risks. The sorption of CIP and ENR in soil is influenced by various factors. Soil cations (i.e., Na+, K+, Mg2+, and Ca2+) and artificially introduced ions (NH4+) can affect the sorption behavior of CIP and ENR in alkaline agricultural soils through mechanisms such as ion exchange and competitive sorption. To investigate the effects of ionic strength and ion type on the sorption of antibiotics in alkaline agricultural soil, batch equilibrium experiments were conducted in this study. The results showed that the affinity of alkaline farmland soil to CIP and ENR was poor, and Kd was only 159 L/kg and 89 L/kg, respectively. Increases in temperature and pH inhibited CIP and ENR sorption on soil. Mineral elements in the soil strongly inhibited CIP and ENR sorption. Conversely, NH4+ promoted the Kd values of CIP and ENR by 46% and 221%, respectively. Additionally, under different influencing factors, both the sorption affinity (Kd) and sorption amount of ENR were lower than those of CIP. These findings indicate that ENR has a greater migration potential and poses a greater environmental risk in agricultural soils. Alkaline soil and mineral elements increase the migration potential of CIP, ENR, but the introduction of NH4+ in agricultural production can weaken the migration potential of them.

Dual-functional lignocellulosic mulch as agricultural plastic alternative for sustained-release of photosensitive pesticide and immobilizing heavy metal ions

The extensive utilization of non-biodegradable plastic agricultural mulch in the past few decades has resulted in severe environmental pollution and a decline in soil fertility. The present study involves the fabrication of environmentally friendly paper-based mulch with dual functionality, incorporating agrochemicals and heavy metal ligands, through a sustainable papermaking/coating technique. The functional paper-based mulch consists of a cellulose fiber web incorporated with Emamectin Benzoate (EB)@ Aminated sodium lignosulfonate (ASL). The spherical microcapsules loaded with the pesticide EB exhibited an optimal core-shell structure for enhanced protection and controlled release of the photosensitizer EB (Sustained release >75 % in 50 h). Meanwhile, the ASL, enriched with metal chelating groups (-COOH, -OH, and -NH2, etc.), served as a stabilizing agent for heavy metal ions, enhancing soil remediation efficiency. The performance of paper-based mulch was enhanced by the application of a hydrophobic layer composed of natural chitosan/carnauba wax, resulting in exceptional characteristics such as superior tensile strength, hydrophobicity, heat insulation, moisture retention, as well as compostability and biodegradability (biodegradation >80 % after 70 days). This study developed a revolutionary lignocellulosic eco-friendly mulch that enables controlled agrochemical release and soil heavy metal remediation, leading to a superior substitute to conventional and non-biodegradable plastic mulch used in agriculture.

EFFECTIVENESS OF BIOCHAR AS SOIL AMELIORANT TO INCREASE SMALL SHALLOT BULBS YIELD FROM TRUE SHALLOT SEED (TSS) IN DRYLAND AGROECOSYSTEM

The decline in soil fertility, characterized by extremely low organic matter content, is a common occurrence in agricultural land due to the intensified practices of crop production. These practices often involve the unwise application of chemical fertilizers and a lack of recycling agricultural waste as organic fertilizers. This study aimed to investigate the impact of biochar on the yield of small shallot bulbs grown from true shallot seed (TSS) in a dryland agroecosystem. The experimental trial was conducted using a randomized block design, incorporating two factors: organic amendments (biochar, manure, and biomass) and TSS varieties (Tuk-tuk, Sanren, and Trisula). The results demonstrated that the use of biochar, particularly in the Trisula variety, resulted in the highest production of mini-tubers, with an average of 4.5 tubers per seed. In comparison, the Sanren variety yielded 1.8 bulbs per seed, while the Tuk-Tuk variety yielded 1.2 bulbs per seed. Furthermore, the application of biochar had a positive influence on soil properties, such as increased levels of organic carbon (C- organic), availability of phosphorus (P-available), and cation exchange capacity (CEC) in dry soils. The utilization of biochar as an organic amendment demonstrated its potential to enhance shallot bulb yield, particularly in the Trisula variety, within a dryland agroecosystem.

Exploring farmer’s assessment of soil quality and root yield in cassava-based cropping systems

Farmers’ knowledge of soil quality and yield assessment were evaluated among cassava farmers in southwestern Nigeria. Data were collected on farmers’ demography, farming experience, criteria for selecting a site for cassava cultivation and preferences for those criteria, farmers’ methods of yield prediction and how it compares with the scientific approach, farmers’ agronomic knowledge and how it relates to the realities of climate change and soil fertility decline. The modal age class of the farmers is 45–55 years, and most of the farmers are male. The results show that farmers use a combination of soil and vegetation-based criteria to assess soil quality from which the decision to cultivate a given land is made. Among the soil-based criteria, soil drainage, colour, and depth rank the most and most used. Most of the farmers assessed yield before harvesting through green healthy leaves (25 %), large and shiny stems (25 %) and soil cracks (50 %). The predicted and measured cassava yields on farmer-managed farms were comparable, with an R2 of 0.63, although farmers overestimated the cassava root yield. There is a unanimous consensus among farmers that yield has declined in the last decade, with a mean of 36 %. The main cause of yield decline was attributed to declining rainfall and poor soils. Our study concluded that farmers have a good understanding of soil health and cassava agronomy through a process of trial and error and ingenuity as farmers’ local indices were consistent with conventional soil health indicators. It was suggested that, by recognising and incorporating traditional methods used by farmers to assess soil quality, we could enhance soil management strategies and raise productivity at the farm level.

Identifying limiting nutrient(s) for better bread wheat and tef productivity in acidic soils of north‐west Amhara, Ethiopia

AbstractFood crop productivity is still low because of the decline of soil fertility in Ethiopia, particularly in north‐western Amhara. Fine‐tuning the source and rate of nutrients is required to solve soil fertility problems along landscape positions. Therefore, this study was initiated to investigate the need to apply selected nutrients to tef and wheat in acidic soils. This nutrient omission study was conducted in 74 farmers’ fields of Gozamen and Machakel districts. The omitted nutrients were sulfur (S), zinc (Zn), and boron (B). Potassium (K) was added, consisting of N, P, K, S, Zn, and B (All+K). Nitrogen plus phosphorus (NP) and no fertilizer treatments were used as positive and negative controls, respectively. Furthermore, 50% and 150% of the All+K treatments were also included. The finding revealed that the application of different nutrient types at variable rates had a significant role in the grain and biomass yield of both test crops in the acidic soils. No tef yield and the lowest yield of bread wheat were obtained from the no fertilizer application treatment. The application of All+K had no significant yield advantage compared to NP fertilizer alone. This implies that N and P are the most yield‐limiting nutrients to produce tef and bread wheat, whereas KSZnB nutrients are not yield limiting. Therefore, refining the rates of N and P in acidic soils is needed for the economical use of fertilizers. Finally, applying blended fertilizers without empirical evidence is not recommended for smallholder farmers in the study area.

Determination of the Appropriate Blended Inorganic Fertilizer Rate Recommendation for the Optimal Common Bean (Phaseolus vulgaris L.) Grain Yield and Profitability in the Dawuro Zone, Ethiopia

Soil fertility decline is a significant factor affecting crop production. In a specific area, fertilizer application for a crop depends on soil type and profitability. Moreover, optimizing chemical fertilizer utilization in crop production is crucial from both environmental and economic perspectives. However, there is limited information available on the optimum NPSB fertilizer rate for common bean production in the study area. Thus, the study aimed to establish area-specific NPSB fertilizer rate recommendations for optimal grain yield and profitability of common bean. The field experiment was conducted in two locations in the 2019 and 2020 cropping seasons. The treatments included 0, 25, 50, 75, 100, 125, 150, 175, and 200 kg·ha−1 NPSB fertilizer rates, and they were planted using a randomized complete block design with three replications. The combined location analysis of variance indicated that the application of NPSB fertilizer significantly influenced plant height, number of pods per plant, number of seeds per pod, hundred-seed weight, biomass yield, grain yield, and harvest index. The highest grain yields (2815 kg·ha−1 and 3433 kg·ha−1) were recorded with the application of a 125 kg·ha−1 NPSB blended fertilizer rate, while the lowest grain yields (1429 kg·ha−1 and 1500 kg·ha−1) were produced from the nonfertilizer applied plot in Deneba and Wara, respectively. The combined location mean showed that the maximum grain yield (3124 kg·ha−1), followed by 2710 kg·ha−1, was produced by the application of 125 and 100 kg·ha−1 NPSB fertilizer rates, respectively. The data indicate that raising the NPSB fertilizer rate from 0 to 125 kg·ha−1 would greatly boost grain yield in the common bean in both locations in a similar manner. The economic analysis revealed that applying 125 kg·ha−1 of NPSB fertilizer earned the highest net benefits (140453.2 ETB·ha−1) with the highest marginal rate of return (1745.26%). Therefore, for high yield and profitability of common bean, a rate of 125 kg·ha−1 NPSB fertilizer is suggested in the study area and similar agro-ecological zones.

The Intention of Using Biofertilizer Among Shallot Farmers in Nganjuk Regency, East Java Province, Indonesia

The excessive use of chemical fertilizer leads to a critical contribution to the environment, such as the decline of soil fertility and shallot productivity in the future. Whereas biofertilizer is one of the alternative ways to diminish the usage of chemical fertilizer to support sustainable agriculture. However, the majority of shallot’s farmers have a lack of knowledge towards biofertilizer. This study aims to analyze the influence of attitude, subjective norms, and perception toward the intention of using biofertilizers. This research was conducted in September 2022 – November 2022 in Gondang and Rejoso District, Nganjuk Regency, East Java, Indonesia. The respondents are considered by census method, and it is distributed to 140 shallot farmers who consist of biofertilizer users. The data was analyzed by using Partial Least Square (PLS) in order to examine the influence of attitude, subjective norms, and perception towards the intention of using biofertilizer. Overall, it is illustrated that attitude, subjective norms and perception have a positive and significant influence towards the intention of using biofertilizer among shallot farmers.

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.

Soil Health and Nutrient Management

Soil health and appropriate nutrient management are critical components of sustainable agriculture, influencing crop yield, environmental sustainability, and overall food security. The ability of soil to function as a living ecosystem is referred to as soil health. supports plant and animal life while protecting the environment. It refers to how physical, chemical, and biological activity interact in the soil. Mineral matter, organic matter, water, and air are all critical components of soil health, and each contributes to plant growth. Soil health indicators include physical, chemical, and biological factors that help assess the soil's state. For optimal soil health, these indicators must be balanced.
 However, there are significant issues to address, such as decreased soil organic matter, declining soil fertility due to nutrient deficits, physical soil degradation, and chemical soil degradation caused by excessive chemical use. Practices for sustainable soil management are critical for addressing these concerns. Balanced fertilization, organic matter incorporation, crop rotation, cover cropping, reduced tillage, and precision nutrient delivery are examples of these. Mitigating issues such as nutrient pollution, soil erosion, and soil deterioration is critical to maintaining agriculture's long-term viability.

Soil Fertility Assessment and Mapping under Different Land Use Types along Toposequence at Danka Watershed in Dinsho Districts of Bale Highland Oromia, Southeastern Ethiopia

Soil fertility assessment and mapping bases, to increase fertilizer usage efficiency, decision-makers, planners, and soil management in undulating slopes farming of Ethiopian highlands like Bale Highland. The study aimed to assess and map soil fertility status along toposequence under different land use types at the Danka watershed of Dinsho District Bale Highland, Southeastern Ethiopia. Following the initial reconnaissance field survey, 54 composite soil samples were prepared from the three land use types (natural forest, grazing, and cultivated) at three slope positions lower (0 - 10%), middle (10 - 15%), and upper (15 - 30%) at a soil depth of 0 to 20 cm. Finally, the laboratory results were interpolated using the IDW interpolation technique in ArcGIS software 10.5 for the soil fertility status map and further analyzed using R software 4.1.1 Version for mean separation. The study findings indicate that the soil texture class of the study was loam to clay loam, clay loam, and clay to clay loam at the upper, middle, and lower slope positions, respectively. The finding revealed that the values varied from 5.81 – 6.66, 2.07 – 6.25%, 0.13 – 0.71%, 2.83 – 17.56 gm/kg, and 14.04 -38.80 cmol (+)/kg) for the soil pH, organic matter, total nitrogen, available phosphorus, and CEC, respectively. In this study, most of the soil fertility status of the Danka watershed was as follows: natural forest > grassland > cultivated land use types and lower slope > middle slope > upper slope positions. In conclusion, the main factors contributing to the area's declining soil fertility status were monocropping, total crop residue removal, soil erosion, nutrient leaching, and inadequate soil management. The results of the current study offer the basis for the work of farmers, planners, decision-makers, and other agriculture-related stakeholders. Integrated soil fertility management with biophysical soil conservation measures is advisable for cultivated land at all slope positions. Further, a study on slope position-based crop response fertilizer rating for agricultural precision and ensuring food security is recommended in undulating fields of the Danka watershed.

Vulnerability and resilience in the face of climate changes in Senegal's drylands: measurement at the household level and determinant assessment

The resilience capacity of smallholder households is one of the main drivers of their ability to continue to farm and make investments in the fragile dryland regions. This paper aims to assess the resilience profile of smallholder farmers in the face of climate change and the factors influencing it in three dryland sub-regions of Senegal, namely, Louga, Kaffrine, and Thies. We developed a composite index of climate resilience (CICR) using data on farmers' perceptions of climate variability and their perceived ability to withstand, adapt, and bounce back in the event of climatic shocks. Drought, strong winds, and soil fertility decline because of climate change emerged as the main climate hazards impacting smallholder farming systems. The CICR value ranged from −2 for the most vulnerable households to +2 for the most resilient households. On average, all the households were found to be vulnerable, with an average CICR value of −0.2. The LOUGA region was the most vulnerable, with an average CICR value of −0.36, followed by THIES (-0.2). The KAFFRINE region was relatively less vulnerable, with a CICR value of −0.1. Ordered logit model estimates show that the chances of improving CICR decrease with the increase of the household head's age until 59 years. Access to training on climate-smart agricultural (CSA) practices and climate information appeared to have the potential to increase by 171% the chance of the household improving its resilience status. Analysis also shows that one more woman working off-farm or in-home gardening has the potential to multiply by four times the chances of households being more resilient. This highlights the importance of empowering women to enhance household resilience to climate change. The off-farm revenue increased the chance to improve the resilience status of the farm household by 62% and the receipt of transfer revenue by 50%. This study provides a robust method for quantifying resilience or wellbeing and its drivers and enriches our understanding of the resilience ability of farmers to climate change in a West African context. It can be useful in designing effective adaptation interventions and improving the overall wellbeing of smallholder farmers.

Integrated Straw Return with Less Power Puddling Improves Soil Fertility and Rice Yield in China’s Cold Regions

The rice production system in China is facing challenges, including declining soil fertility and a stagnant rice yield. This study aimed to test whether integrating the return of straw to fields with less power puddling could simultaneously enhance soil fertility and rice yields. Therefore, field experiments were conducted in Heilongjiang Province, a key rice-growing region in China, from 2017 to 2021, using three different planting methods: control group (CK), straw return (SR) and straw return integrated with less power puddling (SR + LP). The results showed that small soil aggregates (particle diameter < 0.25 mm) and soil bulk density were significantly decreased when straw return was integrated with less power puddling. These changes contributed to the preservation of soil structure. Simultaneously, this approach significantly increased soil ammonium nitrogen content from 9.9 to 10.9 mg kg−1, organic matter content from 35.0 to 36.2 g kg−1, available nitrogen content from 140.5 to 147.0 mg kg−1 and available potassium content from 128.6 to 136.8 mg kg−1 at mature stage on average. Consequently, the post-heading stored assimilates accumulation of rice was increased from 6.12 to 6.43 t ha−1, and the nitrogen, phosphorus and potassium accumulation of rice were increased by 7.85 kg ha−1, 1.13 kg ha−1 and 5.68 kg ha−1, respectively. These changes ultimately resulted in a higher 1000 g weight and filled grain rate, providing the foundation for higher yields (an increase from 9.31 t ha−1 to 9.55 t ha−1). Furthermore, this approach also increased the net income for farmers by USD 14 t ha−1. In summary, this study demonstrates that integrating straw return with less power puddling can enhance soil’s nutrient supply and retention capacity. This enhancement may boost the absorption and transportation of nutrients, ultimately establishing the groundwork for higher yields and economic benefits by enhancing the 1000 g weight and filled grain rate. Future research should delve deeper into its applicability across different ecosystems and investigate the yield-increasing mechanisms.

Effect of combined use of supplementary irrigation, manure and P fertilization on grain yield and profitability of soybean in northern Nigeria

Declining soil fertility particularly phosphorus deficiency, low organic carbon, moisture stress and high cost of input are factors limiting soybean yield in the Nigeria savanna. Supplementary irrigation, nutrient application and inoculation with Bradyrhizobium could increase the grain yield of soybean. We evaluated the effects of Rhizobia inoculant, phosphorus fertilization, manure, and supplementary irrigation on the nodulation and productivity of a tropical soybean variety in two locations in northern Nigeria in the 2017 and 2018 cropping seasons. The treatments consisted of five input bundles: Supplementary irrigation +17.5 kg P ha−1 + 4 t ha−1 poultry manure + nodumax inoculant (S + P + M + I); 17.5 kg P ha−1 + 4 t ha−1 poultry manure + nodumax inoculant (P + M + I); 17.5 kg P ha−1 + nodumax inoculant (P + I); 17.5 kg PP ha−1 (P); and nodumax inoculant (I). Economic analysis was done to determine the benefit-cost ratio (BCR) for each input bundle. In Kano, the input bundle S + P + M + I produced mean number of nodules that were 38, 102, 200 and 352% higher than that of input bundles P + M + I, P + I, P and I, respectively. At Lere, the application of input bundle S + P + M + I increased mean number of nodules by 33, 81, 93 and 182% over that of input bundles P + M + I, P + I, P and I, respectively. Mean grain yield in Kano was greater for input bundle S + P + M + I over P + M + I, P + I, P and I bundles by 31, 50, 64 and 223%, respectively. In Lere, grain yield for input bundle S + P + M + I was higher than that of input bundles P + M + I, P + I, P and I only, by 27, 47, 41 and 184% respectively. The input bundle P + M + I produced the highest BCR (1.4) in Kano and application only of P produced the highest BCR (1.3) in Lere. Supplementary irrigation was not found to be profitable due to the high cost of supplementary irrigation.The application of P with or without manure/inoculant is recommeded for profitable soybean production in the savannas of Nigeria.

Seaweed on Productivity and Profitability of Major Crops in India

This article explores the transformative potential of seaweed in enhancing the productivity and profitability of major crops in India. Indian agriculture, a cornerstone of the nation's economy, faces numerous challenges, including declining soil fertility, water scarcity, and the pressing need for sustainable farming practices. Seaweed emerges as a promising solution, thanks to its rich nutritional profile, including essential minerals and growth hormones beneficial for crops. The article delves into various case studies and research findings that demonstrate significant improvements in crop yields and quality when seaweed-based products are employed. It also assesses the economic implications, highlighting the cost-effectiveness and increased profitability for farmers due to higher yields and improved crop quality. Additionally, the environmental benefits of seaweed, such as enhancing soil health, promoting sustainability, and reducing chemical usage, are discussed. Despite its potential, the article acknowledges challenges in scaling seaweed production and the need for further research and policy support. The conclusion emphasizes seaweed's role in revolutionizing Indian agriculture by offering a sustainable, profitable, and environmentally friendly approach to enhancing crop productivity.

Reaction of Selected Citrus Cultivars to Pseudocercospora Leaf and Fruit Spot Disease Under Natural Infection in Northern Uganda

Citrus is an important crop among many resource constrained subsistence farmers living in rural areas of Uganda. Citrus production is affected mainly by drought, declining soil fertility, pests and diseases. Among diseases, citrus leaf and fruit spot disease caused by fungus Pseudocercospora angolensis is currently one of the major constraints to the production of citrus in Uganda where millions of people rely on the crop for nutritional security and household income. The disease can lead to 50-100% fruit yield loss depending on environmental conditions, disease management and weather conditions. In order to identify resistance to P. angolensis, a study was conducted to identify variability for citrus leaf and fruit spot resistance from adapted commercial cultivars as an initial step in developing integrated disease management strategy. Six cultivars were assessed. The screening was under natural infection conditions in disease hot spots in northern Uganda in 2014a and 2014b seasons. The results showed significance difference (p < 0.01) for Area Under Disease Progressive Curve (AUDPC) for number of leaves with P. angolesnis symptoms and number of lesions. Subsequently, the study identified Kuno as resistant and Tangelo as less susceptible to Pseudocercospora leaf and fruit spot infection, and they could be recommended for citrus leaf and fruit spot disease control.

Analysis of physiological response and differential protein expression of Paramichelia baillonii saplings under phosphorus deficiency.

Paramichelia baillonii is a rare and fast-growing tree species in subtropical China. The acidic red soil in southern China severely limits its growth as it lacks sufficient available phosphorus (P), resulting in declining soil fertility and nutrient availability. The effect of P deficiency on P. Baillonii growth, root attributes, and physiological response has not yet been reported. Understanding the adaptability of P. baillonii to low-P conditions can improve afforestation and soil management in southern China. Therefore, we conducted a pot experiment on 2-year-old saplings and treated them with different P levels. Results showed that P deficiency (0-5 mg L-1 ) decreased growth attributes, root morphological traits, and nutrient uptake of P. baillonii saplings compared to control (CK). Similarly, reduction in chlorophyll a, b, total chlorophyll, net photosynthetic rate (Pn), transpiration rate (Tr), and Gs were seen in low P treatment saplings compared to CK. Whereas superoxide dismutase, peroxidase, malondialdehyde, acid phosphatase activity, and soluble protein content increased with increasing P-deficiency up to 5 mg L-1 , and soluble sugar showed oppsite trend. Moreover, the proteomics analysis identified 2721 proteins, 196 showing differential expression, with 90 up- and 106 down-regulated. Importantly, the metabolic activities increased in the pentose phosphate pathway, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, and phenylpropanoid biosynthesis pathways to sustain regular plant growth under P deficiency. This study delves into the dynamic morpho-physiological and proteomic changes in response to P deficiency. Overall, growth and nutrient uptake were reduced, countered by adaptive biochemical and proteomic shifts, including heightened antioxidant activities and modifications in metabolic pathways, highlighting the resilient strategies of P. baillonii saplings under P deficiency.

Assessing the Potential of Extra-Early Maturing Multiple Stress-tolerant Maize Hybrids Under Different Rates of Nitrogen

Decline in soil fertility is a major constraint to maize production. This study aimed to assess the agronomic performance of improved maize varieties under different nitrogen rates to identify low nitrogen tolerant varieties. Five multiple stress-tolerant maize hybrids, developed by maize improvement program of the International Institute of Tropical Agriculture (IITA), and an open-pollinated variety used as check were evaluated under three levels nitrogen at two locations during 2019 growing season. The experiment was laid out in a split-plot experiment with three replications at each location. Nitrogen rates and varieties were the main and secondary factors, respectively. Data collected on grain yield and its related traits and were subjected to analysis of variance at 5% level of significance. The average grain yield of the six varieties under different nitrogen levels ranged from 2.2 t/ha at 0 kgN/ha in Angaradébou to 5.3 t/ha at 76 kgN/ha in Komkoma. Hybrid TZEEQI 342 × TZEEQI 7 showed high grain yield (4.0 t/ha) across the two agro-ecologies while varieties TZEE-W Pop STR QPM Co × TZEEQI 7 (3.7 t/ha) and TZdEEI 91 × TZEEI 21 (3.6 t/ha) had comparable grain yield. These hybrids were also less susceptible to nitrogen stress. They are the promising genotypes for Angaradébou localities while farmers around Komkoma should continue to cultivate TZEE-W Pop DT STR QPM.

Farmers’ Perceptions of Maize Production Constraints and the Effects of Push–Pull Technology on Soil Fertility, Pest Infestation, and Maize Yield in Southwest Ethiopia

This study aimed to analyze farmers’ perceptions of maize production constraints and determine the effects of push–pull technology (PPT) on crop yield, pest control, and improving soil fertility status. Increasing fertilizer prices and pesticide prices, FAWs (fall armyworms) and stemborers, declining soil fertility, and drought are the main maize production constraints in the area. Seventy percent of the respondents indicated that an increase in input prices such as those of fertilizer and seeds is the major constraint in the area, while FAWs (55%) and stemborers (44.3%) were ranked the third and fourth major constraints. About 67% of farmers reported that stemborer damage to maize in PPT plots was either minimal or non-existent. Fifty-five percent of farmers stated that the damage caused to maize by FAWs was low or that there was no damage in PPT plots. PPT reduced stem borer infestation from 83% to 44%. The yield gained from PPT plots ranged from 18% to 31%. Soil samples taken from PPT plots showed improved soil organic carbon, organic matter, total nitrogen, and cation exchange capacity.