Fertilizer Rates Research Articles

The LTAR Cropland Common Experiment at the Kellogg Biological Station.

The Kellogg Biological Station Long-term Agroecosystem Research site (KBS LTAR) joined the national LTAR Network in 2015 to represent a northeast portion of the North Central Region, extending across 76,000 km2 of southern Michigan and northern Indiana. Regional cropping systems are dominated by corn (Zea mays)-soybean (Glycine max) rotations managed with conventional tillage, industry-average rates of fertilizer and pesticide inputs uniformly applied, few cover crops, and little animal integration. In 2020, KBS LTAR initiated the Aspirational Cropping System Experiment as part of the LTAR Common Experiment, a co-production model wherein stakeholders and researchers collaborate to advance transformative change in agriculture. The Aspirational (ASP) cropping system treatment, designed by a team of agronomists, farmers, scientists, and other stakeholders, is a five-crop rotation of corn, soybean, winter wheat (Triticum aestivum), winter canola (Brassicus napus), and a diverse forage mix. All phases are managed with continuous no-till, variable rate fertilizer inputs, and integrated pest management to provide benefits related to economic returns, water quality, greenhouse gas mitigation, soil health, biodiversity, and social well-being. Cover crops follow corn and winter wheat, with fall-planted crops in the rotation providing winter cover in other years. The experiment is replicated with all rotation phases at both the plot and field scales and with perennial prairie strips in consistently low-producing areas of ASP fields. The prevailing practice (or Business as usual [BAU]) treatment mirrors regional prevailing practices as revealed by farmer surveys. Stakeholders and researchers evaluate the success of the ASP and BAU systems annually and implement management changes on a 5-year cycle.

Exploring the use of POLY4 for the improvement of productivity, peanut quality, and soil properties in Southern India.

Polyhalite-based POLY4, a multi-nutrient source containing potassium, calcium, magnesium, and sulphur, is increasingly recognised for its potential to improve crop yields and soil health in agricultural systems. It is also been considered as a feasible approach for addressing the deficiency in potassium, calcium, and sulphur within a single application source. The present study aimed to investigate the impact of polyhalite-based POLY4 application, either as a complete or partial substitute for traditional potassium fertiliser and gypsum supplement, on the improvement of peanut (Arachis hypogaea) growth and soil quality. An extensive field study was conducted from 2021 and 2022, employing ten distinct nutrient management treatments with three replications in a randomised complete block design. The findings of the study indicated that the application of polyhalite (POLY4) in conjunction with only NP fertilisers resulted in a higher yield advantage (approximately 150-200 kg ha-1) than in plots treated with NPK + gypsum (at 500 kg ha-1) and control plots. The application of polyhalite-based fertiliser (POLY4) at a rate that was 100% equivalent to K along with NP fertilisers resulted in a significant increase in pod yield (5.3-12.8%) over NPK + gypsum and control plots. Thus, the increased crop yield led to an increase in gross returns of 4.88% and in net returns of 4.28% with the application of POLY4 (100%) + NP fertilisers over other treatments. Likewise, variable rates of conventional fertilisers along with POLY4 (100% recommended) + NP + gypsum at 310 kg/ha significantly increased the linoleic acid content (38.5%), oleic acid content, and oil content (48.1%) by reducing palmitic acid (11.96%) content in the groundnut seed. Interestingly, POLY4 use at the 50% recommended rate also resulted in yields that were comparable with those obtained with 100% NPK. Therefore, applying POLY4, a polyhalite fertiliser, in either a 100% or 50% equivalent of essential K can be an effective way of increasing the production of peanut crops and promoting agricultural sustainability.

Modeling and Optimization of Maize Yield and Water Use Efficiency under Biochar, Inorganic Fertilizer and Irrigation Using Principal Component Analysis

This study was conducted to predict the grain yield of a maize crop from easy-to-measure growth parameters and select the best treatment combinations of biochar, inorganic fertilizer, and irrigation for the maize grain yield and water use efficiency (WUE) using the Principal Component Analysis (PCA) technique. Two rates of biochar (0 and 20 t ha−1) and fertilizer (0 and 300 kg ha−1) were applied to the soil, with maize crop planted, and subjected to deficit irrigation at 60, 80, and 100% of full irrigation amounts (FIA). Maize growth parameters (number of leaves—NL, leaf area—LA, leaf area index—LAI, and plant height—PH) were measured weekly. The results showed that the developed principal component regression (PCR) from the easy-to-measure growth parameters were strong and moderate in predicting the maize yield and WUE, with coefficient of determination; r2 values of 0.92 and 0.56, respectively. Using the PCA technique, the integration of irrigation with the least amount of water (60% FAI) with biochar (20 t ha−1) and fertilizer (300 kg ha−1) produced the highest ranking on grain yield and water use efficiency. This optimization technique showed that with the adoption of the integrative approach, 40% of irrigation water could be saved for other agricultural purposes

Micronutrients concentration and content in corn as affected by nitrogen, phosphorus, and potassium fertilization

AbstractThe interaction between nitrogen (N), phosphorus (P), and potassium (K) fertilizers significantly impacts the uptake of micronutrients in corn, influencing their availability in soil and uptake by plants. Understanding the interaction of macro‐ and micronutrients is a prerequisite to targeting nutrient balance in crop production. Therefore, a 2‐year field experiment was conducted to determine the effect of NPK fertilization on micronutrient uptake of rain‐fed corn (Zea mays L.). A randomized complete block design was employed with 12 treatments replicated three times. Different combinations of N, P, and K fertilizer rates were investigated for micronutrient concentration and uptake in rain‐fed corn. Findings revealed the order of nutrient accumulation in corn plants: iron (Fe) > manganese (Mn) > zinc (Zn) > copper (Cu). Nitrogen application influenced nutrient concentrations and uptake. Increasing N rates increased micronutrient concentrations in corn grain, except for Cu. Interestingly, Cu content in grains exhibited no correlation with nutrient supply, biomass, or other concentrations. As the N application rate increased, micronutrient content increased at early growth stage and physiological maturity. Phosphorus application showed negligible impact on grain micronutrient concentration and uptake. However, K application notably increased Mn, Fe, and Cu uptake in grains. This study underscores the need to consider not only grain yield but also nutritional quality when determining optimal NPK rates in rain‐fed corn cultivation.

Effects of Various Herbicide Types and Doses, Tillage Systems, and Nitrogen Rates on CO2 Emissions from Agricultural Land: A Literature Review

Although herbicides are essential for global agriculture and controlling weeds, they impact soil microbial communities and CO2 emissions. However, the effects of herbicides, tillage systems, and nitrogen fertilisation on CO2 emissions under different environmental conditions are poorly understood. This review explores how various agricultural practices and inputs affect CO2 emissions and addresses the impact of pest-management strategies, tillage systems, and nitrogen fertiliser usage on CO2 emissions using multiple databases. Key findings indicate that both increased and decreased tendencies in greenhouse gas (GHG) emissions were observed, depending on the herbicide type, dose, soil properties, and application methods. Several studies reported a positive correlation between CO2 emissions and increased agricultural production. Combining herbicides with other methods effectively controls emissions with minimal chemical inputs. Conservation practices like no-tillage were more effective than conventional tillage in mitigating carbon emissions. Integrated pest management, conservation tillage, and nitrogen fertiliser rate optimisation were shown to reduce herbicide use and soil greenhouse gas emissions. Fertilisers are similarly important; depending on the dosage, they may support yield or harm the soil. Fertiliser benefits are contingent on appropriate management practices for specific soil and field conditions. This review highlights the significance of adaptable management strategies that consider local environmental conditions and can guide future studies and inform policies to promote sustainable agriculture practices worldwide.

Optimization of water and nitrogen management in wheat cultivation affected by biochar application − Insights into resource utilization and economic benefits

In the context of global climate change and natural resource scarcity, agricultural production is facing multiple challenges in improving crop yields and optimizing natural resource use. It is of great practical significance to optimize agricultural practices to achieve sustainable agricultural development. In this study, a two-year winter wheat field experiment was conducted in the Guanzhong Plain, Shaanxi, China, from 2020 to 2022 to assess the effects of biochar, irrigation, and N fertilizer rates on the yield, water-nitrogen use efficiency, and economic benefits of winter wheat. Specifically, biochar was applied to winter wheat at 30 t ha−1 in combination with two irrigation application rates, including regular irrigation (I100; actual evapotranspiration) and deficit irrigation (I80; 0.8 actual evapotranspiration), and three different N fertilizer rates at 210 (NH; conventional applied N rate by local farmers), 160 (NM; moderate N rate), and 110 kg ha−1 (NL; low N rate). The control groups in this study consisted of experimental plots under the NM and N0 (no N) without biochar application. The aboveground dry matter mass (ADM), yield, and net ecosystem economic budget (NEEB) of winter wheat showed increasing trends with increasing N application rates without significant differences between the NH and NM treatments. On the other hand, the water use efficiency (WUE), agronomic N fertilizer use efficiency (aNUE), and N fertilizer recovery efficiency (NRE) showed increasing-decreasing trends with increasing N fertilizer rates, reaching the highest values under the NM treatment scenario. The biochar addition significantly increased the winter wheat yield and WUE (P<0.05). On the other hand, the I80 treatment resulted in higher WUE and irrigation water use efficiency (IWUE) than those under I100 by 5.63 and 13.52 %, respectively. TOPSIS results indicated that the combined I80B1NM treatment was the optimal winter wheat management practice, maintaining high productivity while improving resource use efficiency and economic benefits. The results of the present study provide an important scientific basis and guidance for ensuring efficient and high-quality agricultural products in the Guanzhong Plain and other regions in China with similar climatic characteristics.

Characterization of phosphorus balances in corn silage fields from eight New York dairies

AbstractOptimizing phosphorus (P) application in corn (Zea mays L.) silage production systems to align with crop P requirements while sustaining soil test P (STP) levels can help mitigate environmental risks and enhance farm profitability. The objectives of this study were to characterize P balances of corn silage fields in New York, their drivers, relationships between P balances and field STP and nitrogen (N) balances, as well as the impact of manure application practices on balances. Field‐level balances (supply–uptake) for P and N were derived for 994 field observations across eight dairy farms and 5 years. On average, P balances were low (11 kg P ha−1) with a wide range across farm averages (−11 to 30 kg P ha−1). Across farms, P was applied at higher rates to fields with adequate STP than to lower STP fields, indicating potential opportunities for reallocation of P within farms. Phosphorus balances were positively related to N balances. Manure nutrient utilization indicated that N‐based applications would lead to large positive P balances in all farms. Phosphorus‐based manure applications could cover on average 51% of corn N requirements under current farm manure application practices. This could be increased up to 85% when maximizing the utilization of manure inorganic N. Management alternatives to prevent excessive P balances include improving diet formulation to reduce P excretion, reducing animal density, exporting manure, implementing manure treatment technologies that conserve N and/or remove P, combining appropriate rates of manure and fertilizer, and maximizing manure inorganic N utilization in field applications.

Effects of NPS Fertilizer Rate on Yield and Yield Components of Bread Wheat Production in Degem District, North Shewa Zone, Oromia, Ethiopia

Productivity of wheat was low due to depleted soil fertility and the blanket use of fertilizers. Fertilizer is the most vital input, contributing significantly to final wheat yields although wheat yields have long been low due to a lack of soil test-based site-specific fertilizer recommendations. This study aimed to determine an economically appropriate rate of NPS fertilizer based on calibrated Phosphorus for bread wheat production in the Degem district. The experiments laid out in randomized complete block design (RCBD) with three replications. The treatments were based on already determined Phosphorous critical and requirement factors and consisted of 100% Pc from TSP fertilizer, 25%, 50%, 75%, and 100% Pc from NPS fertilizer and control (without fertilizer). The phosphorus requirement factor (Pf) (5.85), phosphorus critical (Pc) (22 ppm), and optimum nitrogen optimum nitrogen (92 kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) were used from previous studies. Improved bread wheat variety senete was used at 150 kg/ ha seeds rate. The results of a statistical analysis of variance demonstrated that NPS fertilizer rates based on calibrated phosphorus had significant effects on bread wheat production. Partial budget analysis shows the maximum net benefit (101,570.65 Birr ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) with an acceptable marginal rate of return (MRR) (932’52 %) through the application of 75% of Pc from NPS with optimum nitrogen fertilizer use. Consequently, 75% Pc from NPS should be used in the Degem district for bread wheat production, with the optimum nitrogen. Thus, further scaled-up and demonstration of the technologies for bread wheat production in the Degem district.

Greenhouse gas emissions during alfalfa cultivation: How do soil management and crop fertilisation of preceding maize impact emissions?

ContextThe use of alfalfa in rotation with intensive crops is common practice to mitigate the physical and chemical issues arising from intensive farming practices. However, there is a dearth of studies on this practice. Given the current concern regarding climate change and the significant impact agriculture has on greenhouse gas (GHG) emissions, understanding the emissions associated with this practice, as well as the most suitable soil and crop management techniques for their mitigation, is of paramount importance. ObjectiveThe present study aimed to (i) quantify emissions of N2O, CO2 and CH4 in an alfalfa crop following a maize cropping scenario; (ii) to determine which tillage system generates the lowest GHG emissions, and; (iii) to determine how N fertilisation from a preceding intensive maize crop affects GHG emissions during alfalfa cropping period. MethodsA three-year field experiment (2019, 2020 and 2021) was conducted to assess the emissions of N2O, CO2 and CH4 from alfalfa cultivation following a three-year period of irrigated maize. Two soil management practices (no-tillage and conventional tillage) were implemented during both the maize cropping period and the alfalfa establishment. Additionally, the nitrogen (N) fertilisation rates applied to the preceding maize crop were included as a treatment (0, 200, and 400 kg N ha⁻¹, corresponding to zero, medium, and high fertilisation levels, respectively) in a randomized block design with two factors. ResultsEmissions of N2O in alfalfa ranged from 0.05 to 0.32 mg N2O-N m⁻² day⁻¹, being significantly higher only during first month of sampling in the treatments that had received fertilisation. CO2 emissions ranged from 1158 to 4258 mg CO2-C m⁻² day⁻¹. Year-average CH4 fluxes were −0.27 g C ha⁻¹ day⁻¹. The average total dry matter produced by alfalfa was 17700 kg ha⁻¹ year⁻¹, being higher for the no-tillage treatment, though significantly so only during first month of sampling. ConclusionsUnder Mediterranean conditions, the tillage system and mineral N fertilizer rates have a relative effect on greenhouse gas emissions during the alfalfa cropping period. Plots without N fertilization initially produced lower N2O emissions and higher total dry matter, resulting in the lowest scaled emissions. For the tillage treatment, no significant differences were found in emission dynamics, which may be due to the fact that alfalfa does not involve soil disturbance, leading to a homogenization of the treatments. However, the NT treatment showed lower scaled emissions due to higher yields in the first year. Therefore, alfalfa cultivation is characterized by low GHG emissions, high yields, and a notable capacity to mitigate the negative effects of previous intensive crops. SignificanceThis study provides data on GHG emissions during alfalfa cropping in the typical Maize-alfalfa crop rotation under Mediterranean irrigated systems, which is useful for new agricultural policies aimed at reducing pollution in the agricultural sector. Additionally, it demonstrates the capability of this crop to mitigate adverse agronomic and environmental conditions caused by preceding intensive farming practices.

Optimum source, rate, timing, and placement of phosphorus fertilizer for Illinois soybean

AbstractConsistent increases in soybean (Glycine max L.) grain yields over the past decades in Illinois have co‐increased P demand, but—as for many US Midwest states—P fertilizer recommendations are outdated. We evaluated soybean grain yield, P uptake and removal with grain harvest, and P use efficiency in 4 site‐years of field trials on Argiudolls‐Endoaquolls and Fragiudalfs‐Hapludalfs under annual P application treatments of source (monoammonium phosphate [MAP], diammonium phosphate [DAP], triple superphosphate [TSP]), rate (partial vs. full maintenance rate), and timing–placement combination (fall and spring broadcast, spring banding). Substituting ammonium phosphate fertilizers, the most commonly used P fertilizers in the US Midwest, with N‐free TSP supported similar yields and resulted in similar P removal as hypothesized, while avoiding co‐applied N that can be subject to losses primarily via leaching. Soybean yield and grain P removal were unresponsive to rate, timing, and placement even at the partial rate, although banding and spring application may have reduced N loss risk for MAP and DAP. Given the challenges in accurately estimating P removal rate by grain harvest due to the variability in yield and grain P concentrations across years, assessment of P use efficiency should focus on long‐term balance between fertilization (input) and crop removal (output).

Impact of Wheat Seeding Rates with Sugar Beet, Humic Acid and N Fertilizer Rates on Yield and Chemical In Both Crops

Impact of Wheat Seeding Rates with Sugar Beet, Humic Acid and N Fertilizer Rates on Yield and Chemical In Both Crops

Residual Effect of Microbial-Inoculated Biochar with Nitrogen on Rice Growth and Salinity Reduction in Paddy Soil.

Increasing soil and water salinity threatens global agriculture, particularly affecting rice. This study investigated the residual effects of microbial biochar and nitrogen fertilizer in mitigating salt stress in paddy soil and regulating the biochemical characteristics of rice plants. Two rice varieties, Shuang Liang You 138 (SLY138), a salt-tolerant, and Jing Liang You 534 (JLY534), a salt-sensitive, were grown under 0.4 ds/m EC (S0) and 6.84 ds/m EC (S1) in a glass house under controlled conditions. Three types of biochar-rice straw biochar (BC), fungal biochar (BF), and bacterial biochar (BB)-were applied alongside two nitrogen (N) fertilizer rates (60 kg ha-1 and 120 kg ha-1) in a previous study. The required salinity levels were maintained in respective pots through the application of saline irrigation water. Results showed that residual effects of microbial biochars (BF and BB) had higher salt mitigation efficiency than sole BC. The combination of BB and N fertilizer (BB + N120) significantly decreased soil pH by 23.45% and Na+ levels by 46.85%, creating a more conducive environment for rice growth by enhancing beneficial microbial abundance and decreasing pathogenic fungi in saline soil. Microbial biochars (BF and BB) positively improved soil properties (physicochemical) and biochemical and physiological properties of plants, ultimately rice growth. SLY138 significantly had a less severe response to salt stress compared to JLY534. The mitigation effects of BB + N120 kg ha-1 were particularly favorable for SLY138. In summary, the combined residual effect of BF and BB with N120 kg ha-1, especially bacterial biochar (BB), played a positive role in alleviating salt stress on rice growth, suggesting its potential utility for enhancing rice yield in paddy fields.

Optimum Determination of NPSB Fertilizer Rates on Bread Wheat (Triticum asetivum L.) Varieties

The field experiment was conducted at Degam district during main cropping season to investigate the response of bread wheat varieties to NPSB fertilizer rates and identify its economic benefit. Factorial combination of three improved bread wheat varieties (Danda’a, Hidase and Kakaba) and six fertilizer rates [Control, 50, 100, 150, 200 kg ha-1 NPSB fertilizer each supplemented with 92 kg N ha-1 and 64/20 kg NP ha-1 (Blanket recommendation) were laid out in randomized complete block design with three replications. The highest NKS (54.9), AGBM (13.8 tons ha-1), SY (9.4 tons ha-1) and GY (4549kg ha-1) were recorded from 200 kg NPSB fertilizer. Among the varieties the highest NKS (54.3) from Danda’a, TKW (49.3 g) and GY (3351kg ha-1) were recorded from Hidase variety. Variety Kakaba score the highest PH (102.5 cm) and PNT (5 per plant) with combination of 200 kg and 150 kg NPSB fertilizer respectively and reached days to heading and maturity earlier than Danda’a and Hidase. In general, the economic feasibility of the fertilizer over varieties combination indicated that application of 200 kg NPSB ha-1to all varieties Hidase, Danda’a and Kakaba resulted in maximum marginal rates of return 640.14 %, 604.81% and 481.47%, with a net benefit of 97993, 88596, and 82996 ETB respectively. Although, application of 200 kg NPSB ha-1 led to the highest MRR for the Hidase variety as compared to all other treatments and with about a total of 9397 ETB net benefit increment. Therefore, application of 200 kg of NPSB in supplement of 92 kg N ha-1 fertilizer with Hidase variety was the best producing economically profitable with acceptable grain yield.

Pre-scaling up of Improved Tef Variety in Chora District of Buno Bedele Zone Southwestern Oromia, Ethiopia

Pre-scaling up of improved Dursi variety was carried out in Chora district of Buno Bedele zone Southwestern Ethiopia with the objectives to popularize improved Dursi tef variety, to create wider demand towards improved Dursi tef variety and strength stakeholders’ linkage in the study area. The variety was scaled up on ten farmers’ fields those predominantly selected in collaboration with respective three kebeles’ Development Agents based on farmers’ willingness to provide the required land size. The land size of 25 m x 25 m was used where all the recommended agronomic practice like seed rate, fertilizer rate and weed control method were used for the accomplishment of the activity. Training was provided to Dursi growers, development agents and woreda agricultural experts to facilitate further production and dissemination of the variety. Data like number of participants on the training and yield data were recorded and analyzed using simple descriptive statistics. The result revealed that, about 124 (104 male and 20 female) participants were participated on the training. The mean grain yield of 1790 kg ha-1 was obtained which is greater than yield obtained during demonstration trial. Therefore, Dursi variety was recommended for further dissemination across numerous tef producers in the study area and similar agro ecologies.

Optimizing inorganic blended fertilizer application for the maximum grain yield and profitability of bread wheat and food barley in Dawuro Zone, Southwest Ethiopia

Abstract In a specific area, fertilizer application for a crop depends on the soil type and profitability. Optimizing chemical fertilizer utilization in crop production is crucial from an environmental and economic point of view. However, there is limited information available on the optimum NPSB fertilizer rate for the production of wheat and barley in the study area. Thus, the study aimed to establish area-specific NPSB (18.9% N, 16.44% P, 6.95% S, and 0.1% B) blended fertilizer rate recommendations for the optimal grain yield and profitability of wheat and barley. The field experiment was conducted in two locations in the 2021 and 2022 cropping seasons using a randomized complete block design with three replications. The nine treatments included 0, 25, 50, 75, 100, 125, 150, 175, and 200 kg ha−1 NPSB fertilizer rates. Growth, yield, and yield component data in wheat and barley were collected from randomly selected individual plants and the net plot area. An economic analysis was conducted for grain yield using the procedure established by the International Maize and Wheat Improvement Center. The analysis of variance results showed that blended fertilizer significantly (p &lt; 0.01) affected plant height, number of productive tillers, spike length, number of kernels, thousand seed weight, biomass yield, grain yield, and harvest index traits. The application of a 150 kg ha−1 NPSB rate produced the highest grain yield (5419.0 kg ha−1) in wheat, whereas the application of a 125 kg ha−1 NPSB rate gave the maximum grain yield (4708.0 kg ha−1) in food barley. The economic analysis revealed that the application of a 150 kg ha−1 NPSB fertilizer rate for wheat gave the highest net benefits (309711.50 ETB ha−1) and marginal rate of return (MRR) (4096.96%), while the application of a 125 kg ha−1 NPSB fertilizer rate for barley obtained the highest net benefits (184424.00 ETB ha−1) and MRR (2195.39%). Therefore, to optimize the productivity and profitability of wheat and barley in the study area and similar agroecologies, farmers are recommended to use 150 kg ha⁻¹ NPSB for wheat and 125 kg ha⁻¹ NPSB for barley.

Soil Test-Based Crop Response Phosphorus Calibration Study on Bread Wheat (Triticum Aestivum L) in Liban Chukala District, East Shewa Zone, Oromia, Ethiopia

Nutrient mining due to sub-optimal fertilizer use on one hand and unbalanced fertilizer use on the other have favored the emergence of multi-nutrient deficiency in Ethiopian soils. Therefore, the study was conducted on twenty-one farmers’ fields in the Liban Chukala District of East Shewa Zone of Oromia, during the main cropping seasons of 2019-2022. The study aimed to determine the economically optimum rate of nitrogen fertilizer in the first year. However, in the second two consecutive years the experiment was conducted to determine phosphorus critical (Pc) and phosphorus requirement factor (Pf and the treatments consisted of six levels of phosphorus (0, 10, 20, 30, 40, and 50) kg ha-1 combined with a single level of nitrogen (69 kg ha1) that gave a total of seven treatments. The experiments were laid out in randomized complete block design (RCBD) with two replications and the gross plot, size was 4 m x 5 m (20 m2) was used to determine phosphorus critical (Pc) and also harvested from 4m2 plot areas. The analysis of variance indicated that, thousand kernels weight, and harvest index were not significantly (p&lt;0.05) influenced by applied NP fertilizers. On the other hand, the analysis of variance indicated that Plant height, spike length, number of seeds per spike, biomass yield, and grain yield were highly significantly (p &lt;0.01) influenced by soil test-based phosphorus fertilizer application. The result indicated that the highest (87.82 cm) plant height, the highest (1013 kg ha-1) biomass, and the highest (4517 kg ha-1) grain yield were recorded by 40 kg P ha-1. Moreover, 23ppm phosphorus critical (Pc) and 9.86ppm phosphorus requirement factor (Pf) were identified for bread wheat production for the farmers of Liban Chukala District.

Effect of Irrigation Depth and Nitrogen Fertilizer Rates on Pepper (Capsicum annum L.) Yield and Water Use Efficiency in Tselemty District, Tigray, Ethiopia

Optimizing agricultural crop production involves utilizing proper irrigation and fertilization techniques. A two-year experiment conducted in the Tselemty district during the off seasons of 2019 and 2020 aimed to assess the impact of varying irrigation levels and nitrogen fertilizer application rates on the growth, yield, and crop water productivity of pepper. The study included three irrigation levels (75%, 100%, and 125% of the required irrigation) and three nitrogen fertilizer application rates (75%, 100%, and 125% of the recommended amount). Analysis of the results using Gen-Stat software revealed that most pepper yield attributes were not significantly affected by the different irrigation and fertilizer levels. However, the marketable yield showed significant variation based on the combined application rates. The research indicates that, under ideal circumstances, the optimal approach for pepper growers is a combination of meeting 100% of the irrigation requirement and applying 100% of the recommended nitrogen fertilizer rate. Nevertheless, in scenarios where water resources are limited and fertilizer expenses are high, a reduced irrigation level of 75% of the requirement coupled with 75% of the recommended nitrogen fertilizer rate could be a viable alternative that does not lead to a substantial decrease in yield.

Optimising Nitrogen Fertilisation in a Potato–Oat Rotation and Implications for Nitrous Oxide Emissions in Volcanic Soils

High nitrogen (N) fertiliser rates are usually applied to increase agricultural yields, leading to high nitrous oxide (N2O) emissions. This is a greenhouse gas that contributes to climate change and depletes the ozone layer. This study aimed to optimise N use efficiency and quantify N2O emission factors (EF1) by measuring the effect of N rates on the yield of a potato-cover crop rotation, apparent N use efficiency (NUE) and N2O emissions. The two-year experiment was carried out on volcanic soils (1.6% carbon, 1.4% N) in southern Chile (40°52′ S, 73°03′ W). Three N application rates were evaluated (80, 150 and 300 kg N ha−1), 35% of which was applied at the planting stage (granular) and 65% at the tubering stage. A control treatment with no N addition was also included. Reducing N fertilisation to 80 kg N ha−1 increased NUE by three times, reduced N2O-N emissions by 33% and reduced emission intensity by 27% without a detrimental impact on crop yield and marketable tuber calibre. No significant difference (p &lt; 0.05) was observed in the N2O emission factor (EF1) because of a low rainfall year. The results suggest that in rainfed agriculture systems, N fertiliser application can be significantly reduced without sacrificing potato yield, favouring the economic and environmental sustainability of potato production.

Effect of slow-release mineral fertilizer on the intensity of phosphorus and potassium mobilization in soil

The search for new technologies for effective regulation of yield and soil fertility is an urgent task. The use of slow-release fertilizers can simultaneously solve both problems – reducing fertilizer rates and increasing the mobilization of soil nutrients. In this paper, the mechanism of slow-release fertilizer effect on the mobilization rate of soil nutrients was investigated using mathematical modeling on the data of field trials with winter wheat. It is shown that in the plots with the slowest dissolving fertilizer (azofoska with 20% content of polyvinyl alcohol), the highest efficiency of azofoska was achieved (an increase in yield of 1.3 t/ha and an increase in mobile forms of phosphorus in the soil of 2.5 mg/100 g soil, potassium – 8.8 mg/100 g soil and nitrate nitrogen – 4.7 mg/100 g soil). The results of phosphorus modeling quantitatively confirmed the assumption that the low rate of dissolution of fertilizer enhances the mobilization of nutrients from soil due to the absence of an excess of plant available nutrients. We provide estimates of the polymer added efficiency for a series of polymer-modified fertilizer. It is shown that this form of fertilizer can be applied to effectively reduce the amount of fertilizer required for the planned harvest, simultaneously with the possibility of bringing the soil to a higher level of effective fertility in major nutrient elements.

REVEALING THE FERTILITY STATUS OF KHANEWAL DISTRICT’S LANDS THROUGH GIS-BASED STUDY

A rapid increase in industrialization and urbanization and population growth requires expansion of agricultural area for food security and raise the importance of soil health assessment to ensure protection and sustainable use of agricultural lands according to their potential. For this purpose, use of digital soil mapping for the analysis of key physicochemical characteristics has been widely used. The GIS enabled the mapping of extensive areas. The purpose of this study is the spatial analysis of soil fertility indicators i.e., soil reaction (pH), Electrical Conductivity (EC), organic matter (OM), micro-macro {Zinc (Zn), Copper (Cu), Iron (Fe), Manganese (Mn), Boron (B)} nutrients in Khanewal districts using GIS-approaches. The result of study shows that soil pH and EC are normal for crop production while almost 95% of samples show low OM, 100% have low available phosphorous content, 33.3% have low K content, 71% have low Fe and 83% have low B content. Therefore, it was recommended that, to continuously incorporate farmyard manure, green manure, and crop residues into the soil over an extended period to address the organic matter deficiency. P, K, Fe and B deficient area should be fertilized with variable rate of respective fertilizer and soil should be periodically tested. It was recommended that the central parts of Khanewal district lands are cultivable as compared to boarder areas.