Potassium Application Research Articles

Nitrogen and potassium application effects on productivity, profitability and nutrient use efficiency of irrigated wheat (Triticum aestivum L.).

The development of robust nutrient management strategies have played a crucial role in improving crop productivity, profitability and nutrient use efficiency. Therefore, the implementation of efficient nutrient management stratigies is important for food security and environmental safety. Amongst the essential plant nutrients, managing nitrogen (N) and potassium (K) in wheat (Triticum aestivum L.) based production systems is citically important to maximize profitable production with minimal negative environmental impacts. We investigated the effects of different fertilizer-N (viz. 0–240 kg N ha-1; N0-N240) and fertilizer-K (viz. 0–90 kg K ha-1; K0-K90) application rates on wheat productivity, nutrient (N and K) use efficiency viz. partial factor productivity (PFPN/K), agronomic efficiency (AEN/K), physiological efficiency (PEN/K), reciprocal internal use efficiency (RIUEN/K), and profitability in terms of benefit-cost (B-C) ratio, gross returns above fertilizer cost (GRAFC) and the returns on investment (ROI) on fertilizer application. These results revealed that wheat productivity, plant growth and yield attributes, nutrients uptake and use efficiency increased significantly (p<0.05)with fertilizer-N application, although the interaction effect of N x K application was statistically non-significant (p<0.05). Fertilizer-N application at 120 kg N ha-1 (N120) increased the number of effective tillers (8.7%), grain yield (17.3%), straw yield (15.1%), total N uptake (25.1%) and total K uptake (16.1%) than the N80. Fertilizer-N application significantly increased the SPAD reading by ~4.2–10.6% with fertilizer-N application (N80-N240), compared with N0. The PFPN and PFPK increased significantly with fertilizer-N and K application in wheat. The AEN varied between 12.3 and 22.2 kg kg-1 with significantly higher value of 20.8 kg kg-1 in N120. Fertilizer-N application at higher rate (N160) significantly decreased the AEN by ~16.3% over N120. The N120treatment increased the AEK by ~52.6% than N80 treatment. Similarly the RIUEN varied between 10.6 and 25.6 kg Mg-1 grain yield, and increased significantly by ~80.2% with N120 as compared to N0 treatment. The RIUEK varied between 109 and 15.1 kg Mg-1 grain yield, and was significantly higher in N120 treatment. The significant increase in mean gross returns (MGRs) by ~17.3% and mean net returns (MNRs) by ~24.1% increased the B-C ratio by ~15.1% with N120 than the N80 treatment. Fertilizer-N application in N120 treatment increased the economic efficiency of wheat by ~24.1% and GRAFC by ~16.9%. Grain yield was significantly correlated with total N uptake (r = 0.932**, p<0.01), K uptake (r = 0.851**), SPAD value (r = 0.945**), green seeker reading (r = 0.956**), and the RIUEN (r = 0.910**). The artificial neural networks (ANNs) showed highly satisfactory performance in training and simulation of testing data-set on wheat grain yield. The calculated mean absolute error (MAE), mean absolute percentage error (MAPE) and root mean square error (RMSE) for wheat were 0.0087, 0.834 and 0.052, respectively. The well trained ANNs model was capable of producing consistency for the training and testing correlation (R2 = 0.994**, p<0.01) between the predicted and actual values of wheat grain yield, which implies that ANN model succeeded in wheat grain yield prediction.

Interactive Effect of Potassium and Zinc on Growth, Yield, Quality and Economics of Green Gram (Vigna radiata L.) under Semi-arid Region of South-west Haryana

Background: Pulses are having a number of constraints in their production as compared to their potential in India. Green gram is an important pulse crop of the country after chickpea and pigeonpea lacks optimum fertilizer management, which leads in reduced growth and yield. The current study aimed to study the effects of different levels of potassium and zinc application on growth, yield attributes, yield and quality of green gram. Methods: The field study was conducted during Kharif 2018 at Regional Research Station, CCS HAU, Bawal on green gram cultivar MH-421. The experiment was laid out in a split-plot design with three replications and treatments comprising four levels of potassium in main plots (0, 10, 20 and 30 kg K2O ha-1) and four levels of zinc in subplots (0, 12.5, 25 and 37.5 kg ZnSO4 ha-1). Result: The results indicated that growth parameters like plant height, number of branches, number of pods, number of seeds and dry matter production were released due to the application of potassium and zinc. The number of nodules, their fresh weight and quality parameters like protein content and seed index significantly increased with the application of potassium up to 20 kg K2O ha-1, but non-significant increment with zinc application. Seed and straw yield increased significantly with potassium and zinc application up to the levels of 20 kg K2O ha-1 and 25 kg ZnSO4 ha-1, respectively. Higher net monetary returns of Rs. 31528 ha-1 with B:C ratio (1.61) was recorded under the treatment combination K20Zn25 (20 kg K2O ha-1 along with 25 kg ZnSO4 ha-1). It was concluded that higher green gram yield with better quality and more net return was achieved when potassium and zinc were applied @ 20 kg K2O ha-1 and 25 kg ZnSO4 ha-1, respectively.

Quality of Reclaimed Domestic Water Irrigated Peppers - NPK Coupling Model and Optimized Combination Solution

Focusing on the coupling between the NPK content in Reclaimed domestic water irrigated peppers and capsaicin, a field experiment in the three-factor, five-level quadratic general revolving combination design was conducted for an in-depth analysis of capsaicin content coupling model by testing the significance of regression equation and coefficient with regression equation. The test result shows that : (1) factors affecting the content of capsaicin are in order of nitrogen fertilizer application level (x1) &gt; nitrogen fertilizer application level (x2) &gt; potassium fertilizer application level (x3) according to the main factor effect analysis based on the established capsaicin-NPK coupling model; (2) the nitrogen-potassium interaction effectively improves the content of capsaicin. That is, the content of capsaicin theoretically tend to be 0g.kg-1 when both the nitrogen fertilizer application level and the level of potassium fertilizer application level are at the lowest; when the amount of nitrogen and potassium fertilizers application increases, the content of capsaicin increases accordingly. Medium nitrogen combined with medium potassium may result in the highest level of capsaicin content which can reach 0. 068g.kg-12 when the level of nitrogen and potassium fertilizers application reaches 120 g.kg-1 and 112.5g.kg-1 respectively . Under the circumstance of certain volume of potassium fertilizer application, the content of capsaicin further increases with the decrease in the level of phosphorus application. The maximum capsaicin content of 0. 21g.kg-1 is achieved when the level of potassium and phosphorus fertilizer application reaches 120 kg.hm-2 and 60 kg.hm-2 respectively; and (3) the range of the ideal target content of capsaicin in peppers irrigated with the reclaimed domestic water in China’s Ningxia Region and the optimized NPK combination solution are obtained and developed. And in specific: the level of NPK fertilizers application would be 186.15kg.hm-2, 71.17kg.hm-2 and 122.02kg.hm-2 respectively under the condition that the content of capsaicin being greater and beyond 0.12g.kg-1.

Yield Response of Rice to Added Phosphorous and Potassium Fertilizer in the Dry Zone of Sri Lanka

Purpose: Continuous application of Phosphorous (P) and Potassium (K) fertilizer over a long period in rice (Oryza sativa L) cultivation may lead to their accumulation in the soils. So, further addition of such fertilizers may be a waste in rice cultivation and also lead to environmental pollution. Thus, field experiments were carried out to study the yield response of rice to added P and K fertilizer under irrigated conditions in Low Humic Gley soils in the Dry Zone of Sri Lanka. Research Method: For the P response study, an experiment was conducted over three consecutive seasons in a rice field where P fertilizer had not been applied for 10 years before the initiation of the experiment, and for the K response study, an experiment was conducted over two consecutive seasons in a rice field where recommended K fertilizer had been continuously applied before the initiation of the experiment. Data on grain yield and yield components, milling quality, important soil properties, and soil and plant P and K contents were recorded and analyzed statistically. Findings: Grain yield, yield components and milling quality of rice did not respond to added P fertilizer over three consecutive seasons in a rice field where P fertilizer had not been applied 10 years before the initiation of the experiment. Soil P analysis indicated that enough soil P was available to maintain an adequate plant P level so that application of P fertilizer in rice cultivation can be avoided at least for about 11½ years (10 years + three seasons) without affecting grain yield and milling quality in Low Humic Gley soils in the Dry Zone of Sri Lanka while saving the cost for P fertilizer. The short-term response of grain yield in rice to added K fertilizer appeared dependent on the grain yield level obtained. No yield response of rice to added K was observed up to the yield level of about 4 t/ha. Thus, the application of K fertilizer can be avoided over two consecutive seasons without affecting grain yield in rice in Low Humic Gley soils in the Dry Zone of Sri Lanka if the yield level is 4t/ha or lower. Research Limitation: Further studies at different locations in farmers’ fields are needed to confirm the applicability of the findings of the present study in farmers’ fields in the Dry Zone of Sri Lanka. Originality/ Value: Long term (over 11½ years) P response study in rice. Such a long-term P response study in rice has not been reported to date. The short-term K response in rice is dependent on the grain yield level achieved.

Effect of foliar application of potassium with aquaculture wastewater on the growth of okra (Abelmoschus esculentus) and Pangasianodon hypophthalmus in recirculating aquaponic system

A 90-day experimental trial was conducted to evaluate the effect of foliar potassium application with aquaculture wastewater on the growth performance of okra and Pangasianodon hypophthalmus in a media-based recirculating aquaponic system. A completely randomized design (CRD) in triplicates was followed with a fish to plant ratio of 4.7 kg/m3: 6 okra plants per tank. The potassium dosages of 0, 2, 3, 4, and 5 g/L were applied twice a month in control, T1, T2, T3, and T4, respectively. The water quality parameters remained within the favorable limit for aquaponic production. The results showed that the overall growth of okra viz., plant height, leaf number, length, and width was significantly higher in the treatments, particularly in T3 and T4 compared to other treatments and the control. The treatment T4 showed the significantly highest yield (31.26±0.78 g/plant) compared to the control (7.25±1.30 g/plant). The okra yield, pod number per plant, and average weight per pod were significantly influenced by potassium dosage with the highest value observed in T3 (4 g/L) and T4 (5 g/L). The potassium dosage also impacted the branching pattern of okra with the highest number of branches observed in plants sprayed with 4 g/L (T3) and 5 g/L (T4) while control showed no branching. The proximate and mineral composition showed significantly higher crude protein (13.57±0.32%) and potassium content (2306.70±37.76 mg/100 g) in okra pods in T4; while potassium and sulfur content of leaves was found to increase with the increased dosage of potassium application. The fish growth, hematological and antioxidant enzymes parameters showed no significant difference in all the treatments and control. The present study recommends a 5 g/L foliar potassium dosage to enhance okra growth and yield without impairing fish growth performance in okra-P. hypophthalmus aquaponics.

Metabolomics Reveal That the High Application of Phosphorus and Potassium in Tea Plantation Inhibited Amino-Acid Accumulation but Promoted Metabolism of Flavonoid

As leaf-harvest plants, tea trees show unique nutrient requirements, different from those of corn and other field crops. However, the effects of nitrogen (N), phosphorus (P), and potassium (K) application on the accumulation of quality-related compounds and the mechanisms underlying how nutrients affect tea-leaf metabolism have not been well elucidated. Here, fertilizers with different N, P, K ratios were applied to tea plants in pot experiments, and metabolomics based on gas chromatography-mass spectrometry (GC-MS) combined with multivariate statistical and quantitative detections were conducted to assess the responses of quality-related compounds to NPK in tea leaves. An increased proportion of P and K was beneficial for the accumulation of carbohydrates and catechins in shoots, although the total carbon content did not increase significantly. In contrast, a high proportion of P and K input reduced the relative chlorophyll content in shoots, and the contents of free amino acids such as theanine and glutamic acid negatively correlated with P and K nutrient content. Moreover, the metabolism of malic acid in the tricarboxylic acid cycle was highly promoted by increasing the application of P and K. These results validate our suggestion that the application of high amounts of P and K in tea plantations induces the biased reallocation of photosynthates and carbohydrates to the catechin pathway by promoting malic acid metabolism in young tea shoots, which further affects tea quality. The results of this study provide theoretical ground for tea quality improvement by optimizing fertilization strategies.

Effect of Water Stress and Potassium Fertilizer on Growth and Yield of Transplanted Aman Rice

Drought stress affects plant growth and development and ultimately reduces the grain yield of rice. The use of periodical water stress and potassium fertilization may enhance rice tolerance to drought stress. But drought at different growth stages may respond differently which is still unclear. This research work was carried out to determine the effects of different periodical water stress combined with potassium fertilization on growth, yield, leaf gas exchanges and biochemical changes in transplanted Aman rice (cv. BRRI dhan71) grown in the field condition and compare them with standard practice (control). Three levels of water stress (Control: Regular irrigation with 1 cm standing water, periodical water stress for 10 days from 15 days after transplanting (DAT) to harvest and water stress for 10 days after panicle initiation or reproductive phase) and two potassium (K) fertilization levels (41 kg K ha-1 and 51 kg K ha-1) were evaluated in this experiment. The application of water stress for 10 days at the reproductive phase and application of potassium at 51 kg K ha-1 showed tolerance to drought stress by increasing chlorophyll content, proline levels and maximum efficiency of photosynthesis in comparison to other treatments. It was observed that rice yield and other physiological parameters reduced with increasing duration of water stress by periodical water stress for 10 days from 15 DAT to maturity while application of additional potassium fertilizer (51 kg K ha-1) has a slight effect on those parameters. From our observation, 10 days of water stress at the reproductive phase of rice with potassium fertilization at 51 kg K ha−1 produced higher grain yield and yield components that are equivalent to standard practice. It was also observed that the biomass and filled spikelet were not affected by without irrigation for 10 days at reproductive phase. Therefore, it could be stated that the rice variety BRRI dhan71 does not require flood irrigation and water stress for 10 days at the reproductive phase is more appropriate to increase water use and optimum yield of rice. South Asian J. Agric., 8(1&amp;2): 36-44

Phosphorus and Potassium Application Improves Fodder Yield and Quality of Sorghum in Aridisol under Diverse Climatic Conditions

Fodder yield and quality must be improved for sustainable livestock production. A lack of or low application of phosphorus (P) and potassium (P) are among the leading constraints of lower fodder yield and quality of sorghum [most cultivated fodder crop during kharif season (crop cultivation in summer and harvesting during winter] in Aridisol of Pakistan. Therefore, this two-year field study evaluated the role of different P and K levels on fodder yield and quality of sorghum cultivar ‘Ijar-2002’ planted in Multan and Okara districts, Punjab, Pakistan. Seven P-K (kg ha−1) levels, i.e., T1 (40–0), T2 (80–0), T3 (0–40), T4 (0–60), T5 (40–40), T6 (80–40), T7 (60–80) and an untreated T0 (control) were included in the study. Results indicated that individual effects of years, locations and P-K levels had a significant effect on fodder yield and quality. All treatments received an equal amount of nitrogen (i.e., 120 kg ha−1). Application of P-K in Aridisols at both locations significantly improved fodder yield, dry matter yield, and ether contents during both years. The T6 (80–40 kg ha−1) significantly improved yield and quality traits of sorghum fodder except for crude fiber (CF) and acid and neutral detergent fiber (ADF and NDF) at both locations during both years of study. Moreover, fodder harvested from Multan observed significantly higher CF, ADF, NDF, cellulose and hemicellulose contents than Okara. However, sorghum grown in Okara harvested more fodder yield due to more plant height and ether contents. In conclusion, planting sorghum in Aridisols, fertilized with 80–40 kg ha−1 P-K seemed a viable option to harvest more fodder yield of better quality.

Combined effect of salicylic acid and potassium mitigates drought stress through the modulation of physio-biochemical attributes and key antioxidants in wheat

Improving physio-biochemical traits in wheat under drought stress conditions has received more research attention in recent years for better adaptability and higher yield. In this study, we explored the potential bio-physiological mechanisms underlying improved plant growth and water use efficiency in wheat following soil application of potassium (0 and 100 kg ha−1) and seed primed salicylic acid (SA) (150 mg per L) and SA foliar application (100 mg per L) under drought stresses (100%, 60% and 30% FC). Two years' average data revealed that inducing drought stress resulted in a decrease in plant pigments content, growth traits, and plant water status however, the influence was substantially reduced with the combined application of K and SA under drought stress conditions. The SA foliar spray in combination with K had increased chlorophyll a (174% and 83%), chl b (130% and 192%), chl a + b (156% and 120), carotenoid (22% and 11%), proline contents (24% and 29%) leaf relative water content (24% and 29%) while reduced leaf WSD (17% and 20%), WRC (6% and 7%), and WUC (23% and 28%) under mild and severe drought stresses, respectively. The increase in grain yield by 41% and 37% with enhanced water use efficiency was obtained with combined foliar SA and K under mild and severe drought stress, respectively indicating its vital role in overcoming the deleterious effects of drought via regulation of osmotic and metabolic processes and stabilizes cell components. RDA analysis revealed that the studied traits were completely discriminated under severe stress than mild or no drought stress. A positive and significant association was found between plant pigments with seed yield whereas a negative and significant correlation existed between water leaf traits and plant pigments. It was concluded that both foliar SA and seed primed SA with K fertilization combat the adverse effects of drought and improved plant water status as well as growth and bio-physiological traits of wheat under drought stress conditions.

Effects of potassium application on vegetative growth, fruiting, and nutrient status of Kinnow mandarin under Indian sub-tropical conditions

Kinnow mandarin is the predominant citrus crop of Punjab state. The area and production of Kinnow are increasing in the southern–western districts of the state because of its high adaptability, yield potential, and better fruit quality, which ensure higher economic returns to the growers. However, soils of sub-mountain and in some areas of central zones of Punjab are deficient in potassium which hinders the quality and production of Kinnow in these regions. Considering these facts, the present study was undertaken during 2009–2020 to find out the optimum level of potassium fertilization in addition to recommended doses of nitrogen and phosphorous required under sub-mountain and central zones of Punjab. The results showed that soil application of potassium significantly increased the plant height, spread, and canopy volume. Fruit weight, fruit number, yield, TSS, and TSS/acid ratio were also markedly improved with soil application of potassium. Leaf analysis revealed that nutrient uptake like N, K, Mg, Fe, and Cu increased with increased soil K application. However, P, S, Mn, and B did not show any linear trend with an increase in the K application. The results indicated that all rates of K application improved fruit quality and yield in Kinnow. So, it is recommended that soil application of K100 and other recommended doses of nitrogen (N100) and phosphorous (P50) should be made to enhance fruit yield and quality in Kinnow mandarin under sub-mountain and central zones of Punjab state.

Effects of Potassium Fertilization on Sweet Cherry Fruit (Prunus avium L.) Quality and Mineral Content

ABSTRACT Potassium (K) is present in higher concentrations than other macronutrients in cherry fruits and is most often associated with changes in fruit quality. This study was carried out in the Sultandağı district of Afyon province between 2015 and 2017 in the cultivation “ziraat 900” sweet cherry cultivar grafted Prunus padus rootstock on aged 15–20 years. The effects of soil K applications (as potassium sulfate (K2SO4) on sweet cherry quality and mineral content were investigated. Different concentrations of K2SO4 (0, 500, 1000, and 1500 g trees−1) were applied under the canopy at one time before full bloom. After harvested fruit length, fruit weight, flesh firmness, water-soluble dry matter (WDM), and mineral content [Calcium (Ca), Magnesium (Mg), Potassium (K), Phosphorus (P), Iron (Fe), Copper (Cu), Zinc (Zn), Manganese (Mn)] were determined. Fruit quality criteria (fruit length, weight, flesh firmness, and WDM content), fruit K and Cu contents values increased depending on the application of K. It was observed that fruit length increased by 9%, fruit weight by 23%, flesh firmness by 24% and WDM content by 20% due to K applications. Potassium application decreased the content of Ca and Mg. This study indicates that the application of K caused an increase in the fruit quality of the sweet cherry.

Potassium application timing to improve corn K-fertilizer use in the oat-corn sequence: a tracer study for high yielding corn

Corn performance is often unchanged by modifying the potassium fertilizer application timing, especially when soil K is not a limiting factor. Consequently, there is no literature reporting K timing on K-fertilizer contribution (or use) in high-yielding corn fields. We evaluated corn performance and K-fertilizer use based on timings of K-fertilizer application in the oat-corn sequence at subtropical environment with highly weathered soils. Additionally, we propose a timing strategy to ensure high corn use of fertilizer. The crop sequence study was conducted in two field experiments to investigate corn performance with respect to K-leaf, K uptake, and yield. Additionally, we evaluated K-fertilizer use by rubidium as potassium derived from fertilizer and potassium use efficiency. Application timings were two before and three during corn growth and development. Timings did not change corn performance even for late K application, and this was attributed mainly to soil K sufficiency levels. Corn K-fertilizer use, on the other hand, was different and higher for timings before (versus during) corn growth and development. Importantly, timing of K application ∼22 days before corn sowing improved corn K-fertilizer use approximately 2-fold versus the two late timings. Timings in oat or during corn sowing were identical for corn K-fertilizer use. We link our rainfall data with literature K-fertilizer movement (positional aspect), and the corn ability to acquire it. Application of K at 3-weeks before corn sowing constituted the optimal timing for fertilizer supply. This finding will assist farmers in large-scale areas to manage K-fertilizer application to promote higher efficiency.

ALLEVIATION OF WATER STRESS ON SOYBEAN (Glycine max) BY FOLIAR APPLICATION OF POTASSIUM

An experiment was performed in wiry greenhouse at Giza Experimental Research Station (30.0204508, 31.2067921), ARC, during two summer seasons of 2019 and 2020 to determine the optimum potassium requirement for mitigating the adverse effects of water stress and improving photosynthetic rate, oxidative substance, RWC, growth and seed quality of soybean. Soybean plants were exposed to water stress at different growth stages under water limited regimes,i.e100% (control), 88% (moist), 76% (medium) and 64% (dry) as well as Potassium at the concentrations of 1 and 2% K2O in addition to spraying with water (as control) were applied. Increasing water stress up to 64% significantly decreased chlorophyll fluorescence, RWC, LAI, CGR and yield component, in the contrary, proline, lipid peroxidation and total soluble protein content increased in response to water stress. In water stress treatments, plants treated with 2%K2O showed the highest values for chlorophyll fluorescence (Fv/Fm), RWC, LAI, CGR, protein, carbohydrate, oil, N, P, k seed content, germination measurements and yield component, while proline, lipid peroxidation, total soluble protein content and EC gave the lowest values. It seems that the application of potassium in 2%K2O concentration may improve plant functions in both normal and stress conditions.

Effect of potassium and magnesium application on growth, yield and nutrient uptake of rainfed maize in the sub-montaneous region of Punjab, India

Potassium (K) and magnesium (Mg) are essential plant macronutrients responsible for mitigation of biotic and abiotic stresses as well as enhancement in yield of maize. In rainfed maize, low productivity due to imbalanced use of fertilizers, erratic rainfall and periodic dry spells are major constraints. Hence, a field experiment was conducted in rainy season during 2015, 2016 and 2017 on an Inceptisol to optimize the levels of K and Mg in rainfed maize. The experiment consisted of four levels of K; control, K @20 kg ha−1, K@30 kg ha−1 and K 40 kg ha−1 and four levels of Mg; control, Mg@15 kg ha−1, Mg@30 kg ha−1, and Mg@45 kg ha−1. Application of K and Mg improved leaf area Index, chlorophyll content and relative water content in maize. Yield attributes of maize also improved significantly with application of K and Mg over control. Highest grain yield (3205 and 3169 kg ha−1) was recorded with the application of 40 kg K ha−1and 45 kg Mg ha−1, respectively which was at par with 30 kg K ha−1 (3103 kg ha−1) and 30 kg Mg ha−1 (3106 kg ha−1), respectively. The highest net returns (US $347 ha−1) and BC ratio (1.72) was recorded with 40 kg K ha−1 while application of 30 kg Mg ha−1 recorded highest net returns (US $332 ha−1) and BC ratio (1.71). Application of 30 kg K ha−1 and 30 kg Mg ha−1 was found to be optimum to improve growth, yield and nutrient uptake in rainfed maize.

A comparison between the characteristics of a biochar-NPK granule and a commercial NPK granule for application in the soil

Continual application of nitrogen (N), phosphorous (P) and potassium (K) fertilizer may not return a profit to farmers due to the costs of application and the loss of NPK from soil in various ways. Thus, a combination of NPK granule with a porous biochar (termed here as BNPK) appears to offer multiple benefits resulting from the excellent properties of biochar. Given the lack of information on the properties of NPK and BNPK fertilizers, it is necessary to investigate the characteristics of both to achieve a good understanding of why BNPK granule is superior to NPK granule. Therefore, this study aims to investigate the characteristics of a maize straw biochar mixed with NPK granule, before and after application to soil, and compare them to those for a commercial NPK granule. The BNPK granule, with a greater surface area and porosity, showed a higher capacity to store and donate electrons than the NPK granule. Relatively lower concentrations of Ca, P, K, Si and Mg were dissolved from the BNPK, indicating the ability of the BNPK granule to maintain these mineral elements and reduce dissolution rate. To study the nutrient storage mechanism of the BNPK granule in the soil, short- and long-term leaching experiments were conducted. During the experiments, organo-mineral clusters, comprising C, P, K, Si, Al and Fe, were formed on the surface and inside the biochar pores. However, BNPK was not effective in reducing N leaching, in the absence of plants, in a red chromosol soil.

Assessing the reproduction of land resources in the context of achieving food security

The article conducted a study of the level of reproduction of land resources in Russia, in the conditions of the formation of food security. It was revealed that the growth of food production in Russia leads to a decrease in the potential of agricultural land. A significant part of the land occupied by agricultural crops is not fertilized. The introduced volumes of nutrients are insufficient for either simple or extended reproduction. Volumes of fertilizers close to simple reproduction are applied to grain and leguminous crops. An increase in the application of potassium would fully allow for the simple reproduction of land occupied by grain crops. The most critical situation has developed with the lands used for growing sugar beets. The lack of nutrients led to the fact that in 2019 the earth lost more than 200 kg of nitrogen and potassium. The identified situation is a threat to both food and national security. If the current trend continues, the yield will show a downward trend, which, even if costs remain at the same level, will lead to an increase in prices, and, accordingly, to a decrease in food availability. In general, there is a pronounced situation of depletion of land resources. Instead of stimulating the introduction of fertilizers and ensuring low prices for them, the country’s leadership is stimulating food exports. This situation is similar to the export of mineral resources and timber. Grain, like oilseeds, is predominantly exported in a non-processed form, which is inherently a low value-added resource commodity. But the main thing is that soil fertility is actually exported, since the applied fertilizers do not even provide simple reproduction.

Influence of potassium on growth, yield and nutrient uptake of groundnut (Arachis hypogaea) cv. TMV 13

All the crops require larger amounts of macronutrients for sustainable production. In view of this context, a present investigation was conducted during 2018–2019 at farmer's field, Namakkal, Tamil Nadu, India to study the effect of potassium on growth, yield and nutrient uptake of groundnut in cv. TMV 13. The farm is located at 11006’00’’ N latitude and 78004’11’’ E longitude. The experiment was laid out in randomized block design with three replications and nine treatments. The treatments were Absolute control, RDF (NP alone), RDF (NP alone) + 25 kg K2O/ha, RDF (NP alone) + 50 kg K2O/ha, RDF (NP alone) + 75 kg K2O/ha, RDF (NP alone) + 100 kg K2O/ha, RDF (NP alone) + 125 kg K2O/ha, RDF (NP alone) + 150 kg K2O/ha, RDF (NP alone) + 175 kg K2O/ha. The results of the field experiment revealed that application of potassium significantly increased the growth, yield and nutrient uptake of groundnut. Growth attributes, namely, plant height (18.2, 42.4 and 55.2 cm at FS, PFS and HS, respectively), leaf area index (1.58, 3.31 and 3.03 at FS, PFS and HS respectively), dry matter production (2746, 4449 and 5906 kg/ha at FS, PFS and HS respectively), total chlorophyll content (1.83 and 2.29 mg/ha at FS and PFS, respectively) and yield attributes, namely, pod yield (2558 kg/ha), haulm yield (3348 kg/ha), shelling percentage (75.2%), kernel yield (1923 kg/ha) and test weight (44.5 g) were found to be maximum in application of RDF (NP alone) + 100 kg K2O/ha. The treatment also recorded the maximum of total nitrogen uptake (84. 3 kg/ha), phosphorus uptake (24.7 kg/ha) and potassium uptake (103.6 kg/ha). However, the treatment of RDF (NP alone) + 100 kg K2O/ha was on par with the treatment of RDF (NP alone) + 125 kg K2O/ha. The least values of growth, yield and nutrient uptake were recorded in absolute control. In post-harvest soil, the maximum value of available nitrogen content (179.2 kg/ha) and phosphorus content (26.7 kg/ha) were recorded with application of RDF (NP alone) and the maximum potassium content (275.2 kg/ha) was recorded with application of RDF (NP alone) + 175 kg K2O/ha. From the results, the present experiment concluded that the excess levels of potassium application decreased the growth, yield attributes and nutrient uptake of groundnut. The application of potassium as 100 kg K2O/ha enhanced the better yield and nutrient uptake of groundnut.

Effect of nitrogen and potassium management on performance of potato crop

The present investigation was carried out at the experimental farm of Doon (P.G.) College of Agriculture and Allied Science, Rampur, Selaqui, Dehradun during rabi season of 2018-19. The experiment comprised of eight treatments comprising basal and foliar application of nitrogen and potassium fertilizers along with a control treatment arranged in Randomized Block Design (RBD) with three replications. The observations were recorded for various growth and yield parameters. Results of the experiment indicated significant effect of different nitrogen and potash doses application on various parameters. The treatment T8 (50% RDK + Spray of K2SO4 @ 2% at 30 DAP) was found to be the best for improving growth characters, while treatment T4 (RDF160:100:120kg NPK/ha) was found best in terms of yield parameters. Based on the results of present investigation, it could be concluded that application of RDF 160: 100: 120 kg NPK/ ha can still be adopted by the farmers but with split applications of nitrogen and potassium as recommended dose for commercial cultivation of potato under present climatic conditions to achieve higher net returns per unit area provided all other agronomic package of practices are followed.

A Comparative Study of Foliar and Soil potassium Fertilizer on Growth and Yield of Strawberry Cultivated in Non-Heated Greenhouses

This study has been conducted in the non-heated greenhouse of the of Protected agriculture department of the Bakrajo Technical Institute of -Sulaymaniyah Governorate during winter season of 2019 The purpose of this study to determine the effect of soil fertilization and foliar application of potassium with different rates ( 0 as control , 1.5 , 2.5 and 3.gm/L ) on strawberry cv. Rubygem growth and yield. The parameters recorded were number of leaf per plant, number of flower per plant, number of fruit per plant, weight of fruit (gm), total acidity % of fruit (T.A) and total soluble solid (TSS) of the fruit. According to the results of most of the parameters of this study the foliar application of the fertilizer (K) is better than applying the fertilizer of soil in most parameters. The highest value of number of leaf, flower, fruit and fruit weight gained from potassium in rate 1.5gm/L in both methods. While the highest value of total soluble solid (T.S.S) obtained from 3.5gm/L which was %12.87, and the highest value of T.A was significantly gained from the control which was % 0.51. As regards to interaction between soil and foliar fertilizer, the highest number of leaf was gained from control at foliar application without any significant value with the other rates, and the highest significant value in number of flower was gained from 1.5gm at foliar application. While the highest value of fruit weight was gained from foliar application with 3.5gm and soli fertilizer with 1.5gm of potassium without any significant value between the two treatments which are 21.72gm and 20.12gm successively, and the highest significant value of total acidity was gained from control at foliar application which is %0.54. As regards to total soluble solid the highest significant value was obtained from 3.5gm in soil fertilizer which is %14.25.

Testing of macro- and micronutrient nanoparticles on grain crops

The studies were conducted in the northern forest-steppe of the Tyumen region. Under laboratory and field conditions, different forms and dosages of macro- and micronutrient nanoparticles and associated substances were tested in the treatment of seeds and plants of spring triticale and wheat. The preparations had a positive effect on seed germination, while higher rates reduced energy and germination. The germination energy and germination of triticale seeds increased by 4-10% with the application of preparations containing nanoparticles of copper, manganese, molybdenum, biogenic iron, Titan M. Treatment of daily seedlings with manganese, calcium, molybdenum, Titan M, biogenic iron, boron, potassium increased sprout length by 7.8-25% and sprout weight by 6-8% by day 7. Only already developing sprouts responded to the application of potassium. It was noted that the application of biogenic iron causes a 4-10% decrease in laboratory germination of seeds, but promotes the development of the main root. Its increase was 9-12% compared to the control. The inclusion of biogenic iron and silicon in the mixture to the chemical dressing reduced the effectiveness against root rot from 18% at the beginning of the growing season to 30% by the harvesting period. The application of biogenic iron increased the yield by 0,5-0,6 t/ha or 23% in the system of complex crop protection compared to the control and by 0,16-0,23 t/ha with the standard scheme of crop protection. A positive effect of biogenic iron in the treatment of plants during the earing phase as a separate element of the technology and in a tank mixture with fungicides was noted.