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Chloride (Cl−) is applied in coffee at rates as a "macronutrient" in the form of muriate of potash (MOP). Potassium (K+) is one of the most demanded nutrients by the coffee plant, and MOP is one of the most used fertilizers in coffee production. No scientific evidence shows how Cl− applied with MOP influences coffee growth, nutrient uptake, and nitrogen use efficiency (NUE). In order to address these questions, a greenhouse trial over two years and a field trial over four years were conducted. The trials were designed to test the influence of variable Cl−/S ratios on biomass accumulation, nutrient uptake, and NUE. A significant effect of the Cl− rates on growth was observed under greenhouse conditions but a non-significant effect on yield under field conditions. Cl− and S significantly influenced the NUE in coffee. The results allow us to conclude that Cl− rates need to be balanced with S rates, and that Cl− applied at macronutrient rates can improve the NUE in coffee between 7 and 21% in greenhouse conditions and between 9% and 14% in field conditions, as long as the rates do not exceed 180 mg L−1 Cl− and 80 mg·L−1 S in the greenhouse and 150 kg·ha−1·year−1 Cl− and 50 kg ha−1·year−1 S in the field. With the aim to improve the NUE in coffee, the Cl− content in leaves in coffee should be lower than 0.33% of dry matter, and in soil lower than 30 mg·L−1. In practical terms, coffee farmers need to balance K-based fertilizers to avoid the excessive Cl− applications that reduce the nutrient use efficiency, especially the NUE. [ABSTRACT FROM AUTHOR]

There are various challenges that limit crop productivity in developing countries like Ethiopia. Lack of accessible plant nutrients in proper quantity as well as form to plants is an important determinant of reducing agricultural productivity. In this regard, a trial was conducted at Shela Borkoshe on the land owned by the farmer in Sodo Zuriya District, Wolaita Zone, Southern Ethiopia over the planting seasons of 2019 to 2020 with the aim of identifying the appropriate rates of blended nitrogen, phosphorus, sulfur, boron (NPSB), and potassium (K) fertilizer in maize production. The treatments, which were assessed using a factorial randomized complete block design with three replications, comprised of four rates of blended NPSB (0, 50, 100, and 150 kilograms/hectare) and four rates of K (0, 30, 60, and 90 kilograms/hectare K2O). Agronomic traits leaf area, LAI, ear length, seeds per row, seeds per ear, TSW, biomass as well as grain produce have been significantly varied due to NPSB by K fertilizer rates interactions. The highest leaf area (9886.20 ± 343.95 cm2), LAI (7.78 ± 0.26), ear length (32.58 ± 1.46 cm), TSW (160.67 ± 4.85 g), biomass (14941 ± 200.92 kilograms/ha), and grain output (7544 ± 119.49 kilograms/ha) have been attained by combining 150 kilograms/ha NPSB and 90 kilograms/ha K fertilizer rate. Following this, maximum quantity of seeds per row (44.88 ± 1.67) and seeds per ear (705.87 ± 25.61) have been attained from combination of 150 kilograms/ha NPSB and 60 kilograms/ha K fertilizer rates. Economic analysis revealed that maximum net profit (1491 Dollar/ha) and marginal rate of return (MRR) 1196.67% have been achieved from combining 150 kilograms/ha NPSB and 60 kilograms/ha K fertilizer rates. This investigation revealed that the combination of the NPSB fertilizer level of 150 kilograms/ha and 60 kilograms/ha K fertilizer showed superior performance with higher grain yield and economic return over other treatments. Therefore, a combined application of 150 kilograms/ha NPSB with 60 kilograms/ha K fertilizer rates could be recommended for maize production in the study area and similar agro-ecologies. [ABSTRACT FROM AUTHOR]

To achieve the carbonization utilization of Triarrhena lutarioriparia straw and relieve the environmental pressure caused by improper disposal in the Dongting Lake area, the agricultural efficiency of biochar derived from Triarrhena lutarioriparia was clarified. Two typical paddy soils in southern China, namely reddish clayey soil developed from a Quaternary laterite parent material and granitic sandy soil developed from a granite parent material, were selected. Six treatments with different dosage of biochar (0, 1%, 2%, 4%, 6%, and 8% of the soil mass，0-20 cm soil depth) were set. Rice pot experiments were conducted in 2020 to study the effects of different application rates of Triarrhena lutarioriparia biochar on rice nutrient utilization characteristics in two typical soils. The results showed different application rates of Triarrhena lutarioriparia biochar and soil types had certain effects on dry matter accumulation and nutrient uptake by rice organs and aboveground structures. With the addition of biochar, compared with the treatment without biochar, the accumulation of dry matter of rice increased from 0.6% to 18.6% and from 15.5% to 42.4% in the granitic sandy soil and reddish clayey soil, respectively. With the addition of 4% biochar, the accumulation of nitrogen, phosphorus, and potassium nutrients in the rice plant of the treatment increased by 8.6%, 10.5%, and 82.5% in the granitic sandy soil and by 33.8%, 100.0%, and 125.3% in the reddish clayey soil, respectively. The quadratic regression equation and fertilizer – carbon coupling model fitting showed that the optimal addition amounts of biochar in the granitic sandy soil and reddish clayey soil were 2.51% and 4.80% for nitrogen utilization, 4.33% and 7.03% for phosphorus utilization, and 4.67% and 4.81% for potassium utilization, respectively. Therefore, the application of Triarrhena lutarioriparia biochar is conducive to promoting the accumulation and growth of nitrogen, phosphorus and potassium nutrients in rice, and the amount of biochar added and soil conditions are important factors affecting the coupling effect of fertilizer and carbon. [ABSTRACT FROM AUTHOR]

Biochar application has been confirmed as an efficient way to increase the productivity of the agricultural system. However, the potential of biochar combined with reducing fertilization on the yield, and the fertilizer utilization efficiency of the rice (Oryza sativa) farming system on acidic soil remains to be further studied. Field micro-plot experiments with two factors were performed in 2018 and 2019 to evaluate the responses of the rice yield and nutrient utilization to the combined application of biochar (60, 80, and 100 t/ha) and fertilizer reduction (70%, 85%, and standard doses of N-P-K fertilizer). Taoyouxiangzhan and Taiyou 553 were used in the late growing season of 2018 and 2019, respectively. The results showed that compared with the control without adding biochar under standard fertilization, 70% doses of fertilizer application had no negative effects on the yield and the N, P, and K accumulation of rice after biochar application. K accumulation of rice increased with the increase of biochar application. The partial productivity of N, P, and K fertilizers increased as the fertilizer was decreased. The agronomic efficiency of N, P, and K fertilizers significantly increased after the combined applications of biochar and fertilizer. In both years, micro-plots with 70% doses of fertilizer had the highest N and P physiological efficiency, as well as K physiological efficiency in 2019. Compared with the control under standard fertilization, utilization efficiency of N, P, and K fertilizer under different biochar and fertilizer combinations significantly increased by 34.24~75.48%, 27.44~84.84%, and 78.52~166.70%, respectively. To sum up, biochar can partially substitute fertilizer for rice production in acid paddy fields in southern China. When the amount of biochar added is ≥60 t/ha, 70% doses of fertilizer application can still ensure the nutrient absorption of rice, improve the fertilizer utilization efficiency, and ensure the stable yield of rice. [ABSTRACT FROM AUTHOR]

With the passing of the 2014 US farm bill, there is more interest in industrial hemp (Cannabis sativa L. < 0.3% total tetrahydrocannabinol [THC]) grown for cannabinoid production. However, production recommendations that outline fertilizer requirements of cannabidiol (CBD) hemp do not exist. Our primary objective was to identify nitrogen (N) and potassium (K) fertilizer rates for maximizing biomass and CBD yield. A secondary objective was to identify the relationships between N and K rates and total THC and total CBD concentrations. Fertilizer rates from 0 to 224 kg N and 0 to 185 kg K ha−1 were tested separately at four general locations in North Carolina. Two locations were used in 2019 and 2020, while the other two were used only in 2020. Dry weight yield was predicted to increase linearly from 1822 to 3384 kg biomass ha−1 as N rate increased from 0 to 86.8 kg ha−1. Nitrogen rates above 86.8 kg ha−1 were not predicted to increase biomass. Likewise, as N rate increased from 0 to 84.2 kg N ha−1, CBD yield was predicted to increase linearly from 204 to 389 kg CBD ha−1. Additional N was not predicted to increase CBD yield. The CBD and THC concentrations showed a slight bell‐shaped response curve over increasing N rates, ranging from 11.33% to 12.11% and 0.473% to 0.509%, respectively. Potassium application did not affect yield nor CBD and THC concentrations. Results from this work indicate that N is a more limiting factor than K for maximizing CBD hemp biomass production. Core Ideas: The optimal nitrogen (N) rates to maximize biomass and cannabidiol (CBD) yield are 86.8 and 84.2 kg N ha−1, respectively.The CBD or tetrahydrocannabinol (THC) concentrations showed a slight bell‐shaped response curve over increasing N rates.Biomass and CBD yields and CBD and THC concentrations were not affected by K rate. [ABSTRACT FROM AUTHOR]

Potassium (K) in fruit and nut orchards affects productivity, water relations, and crop quality; however, information about K, calcium (Ca), and magnesium (Mg) dynamics in orchard soils is limited. This study evaluates the distribution of K, Ca, and Mg in 30‐cm soil columns following four wetting events over 70 days. Soils were a Hillgate sandy loam, a San Ysidro loam, and a Yolo loam applied with muriate of potash (KCl), microfine sulfate of potash (SOP; [K2SO4]), polyhalite (POLY; [K2SO4·MgSO4·2CaSO4·2H2O]), and an unfertilized control. Soil solution K concentrations measured at 5 cm using a porewater sampler were greater than 1400 mg K L−1 in the Hillgate sandy loam POLY treatment after the first two wetting events. Ca and Mg in soil solution were also greater for POLY when averaged across all four wetting events, likely due to greater Ca and Mg inputs. Extractable K using ammonium acetate, significantly increased after the wetting events resulting in 88% and 75% of the extractable K in the top 0–10 cm of the San Ysidro and Yolo loams, respectively. Leached K accounted for 6.2% of the SOP inputs in the Hillgate sandy, whereas only 0.3% and 1.1% in the San Ysidro and Yolo loams, respectively. Higher K leaching as well as Ca and Mg is likely due to higher cation exchange capacity in loam soils and great porosity in sandy loam soils. Our results show differences in the distribution of K, Ca, and Mg and provide insights into K fertilizer availability for orchard soils. Core Ideas: K balances show applied K recovery in different soil K fractions of 55% for silt loam and 73% for sandy loam.K leaching was greater overall for sandy loam and highest for microfine sulfate of potash in sandy loam.Calcium and magnesium in polyhalite increased K in solution compared to other K fertilizer sources.Fertilizer characteristics have a greater impact on cation distribution in sandy loam than silt loam soils. [ABSTRACT FROM AUTHOR]

The period of cultivation of large-diameter timber stands is affected by the relatively slow initial growth of Picea species. The combination of fertilization and nurturing measures can promote the growth of tree height and ground diameter. In this paper, 12 fixed plots of 10m×10m were randomly set up in a larch understory with 10 a juvenile Picea koraiensis plantations as the study subjects. Fertilizer types were selected as N (N - urea), NP (NP - urea+superphosphate), NPK (NPK - urea+superphosphate+potassium phosphate). Two types of fertilization time were set: (1) pre-middle-late growing seasons fertilization: fertilizer was applied per year at the beginning (mid-May), middle (mid-July), and late (mid-August) of the growing season, with fertilization repeated for four consecutive years. (2) Pre-middle-end growing seasons fertilization: fertilizer was applied per year at the beginning ( mid - May), middle (mid-July) and end (mid-September) of the growing season, with fertilization repeated for four consecutive years. Light-felling was set as follows, after one growing season of fertilization, accretion cutting the upper larch trees, and the stand density was 0. 6 after tending. By studying the effects of fertilization and light-felling on the growth of trees, the aim was to develop fertilization management techniques to promote the growth of juvenile P. koraiensis, so as to shorten the growth cycle of young plantation. The effect of applying NPK fertilizer on promoting the height and diameter growth of juvenile P. koraiensis was better than applying only a single fertilizer or a mixture of nitrogen and phosphorus fertilizers. The annual tree height and ground diameter growth were 41.11 % and 49.81 % higher in the treatments NPK fertilizer applied pre-mid-end growing seasons than those treated with NPK in the premid-late growing seasons. After light-felling, the annual growth of tree height between different years was not significantly different, but that of the ground diameter was significantly different. The annual growth of tree height and ground diameter after three growing seasons were not significantly different from that before light-felling. By combining fertilizer application in the pre-middle-late growing seasons with light-felling treatments, the annual growth of tree height and ground diameter were significantly different from the control group after two growing seasons, only the annual growth of ground diameter was significantly different from the control group after three growing seasons. After three growing seasons of nitrogen, phosphorus and potassium fertilizers (NPK2) combined with light-felling in the pre-mid-end of growing seasons, the annual growth of ground diameter was 153.16 % and 10.31 % higher than that of the control and pre-middle-late of growing seasons NPK fertilizers (NPK1) combined with light-felling. The combination of fertilization and light-felling treatments can increase the annual growth of P. koraiensis ground diameters, reaching a significant level at four consecutive years of fertilization. Fertilizer application at the pre-mid-end stages of the growing season is more effective than at pre-mid-late stages. The research provides a basis for solving the problem of slow growth of P. koraiensis plantation at a young age and shortening the cultivation period of large-diameter timber plantation of P. koraiensis. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As part of eco-toxicological tests on Artemia salina, the impact of the most commonly used fertilizers in Morocco was assessed (Ammonium Sulfate, Ammonium Nitrate, and a mixture of Nitrogen 10%, Phosphorus 30% and Potassium 10%), with Potassium Bichromate (K2 Cr2 O7 ) as reference substance at different concentrations (10, 20, 40, 80, 160, 320 mg/l), for 24 hours. The results of the statistical study revealed that the lethal effects caused by the three agrochemicals increase with the concentration and vary from one substance to another in a significant way. There is a higher sensitivity to ammonium sulphate (the concentration that kills 50% of the animals: 37.32 mg/l ± 6.09) followed by ammonium nitrate the concentration that kills 50% of the animals: 110.7 mg/l ± 7.11), and a mixture of Nitrogen 10%, Phosphorus 30% and Potassium 10% (the concentration that kills 50% of the animals: 143.13 mg/l ± 23.12). Therefore, Artemia salina exhibits sensitivity to agrochemicals and can be considered as a good biomonitoring tool for future toxicological analysis of agrochemicals. [ABSTRACT FROM AUTHOR]

To examine the responses of soil physicochemical properties, nutrients and microbial quantity to grass cultivation at different soil depths in orchards in Xinjiang (China), a database was established for meta-analysis based on collected related literature. The results showed that grass cultivation could improve soil physicochemical properties (e.g. water content, pH, bulk density, total porosity), soil nutrient content (e.g. organic matter, alkali hydrolyzed nitrogen, available phosphorus, available phosphorus, available potassium), and increase the number of soil microorganisms (e.g. fungi, actinomycetes), which indicated that grass cultivation had positive effects on soil in Xinjiang orchards. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tropical Grasslands / Forrajes Tropicales is the property of International Centre for Tropical Agriculture - CIAT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tomato (Solanum lycopersicum L.) is a highly economical and socially important vegetable in the world and a priority crop in greenhouse cultivation. Plant growth and yield increments through the over application of nitrogen and potassium fertilizers are commonplace in soilless culture in many regions of the world. It deteriorates the quality of produce, apart from the ill effects of this malpractice on the economic and environmental sustainability of the cropping system. The utilization of residual nutrients in the plants during subsequent growth stages; carryover effect has not much evidence for hydroponically grown plants. Therefore, this study was to find out the possible influence of the carryover effect of higher dosages of N and K fertilizer application at the vegetative stage on subsequent growth stages of tomato. This experiment was conducted as a replicated trial of different combinations of N and K rates for vegetative and other growth stages. The application of low rates of N and K during the vegetative stage did not affect the total marketable yield, nullifying the carryover effect of K and N plant nutrition of hydroponics tomato. Therefore, the optimum N application rates for vegetative, early reproductive, middle and late reproductive stages of hydroponics tomato were 10, 50, 90 and 140 mg/plant/day, respectively and optimum K rates 50, 200, 300 and 350 mg/plant/day respectively. Growth stage specific combinations of optimum N and K fertilizer application rates were effective in attaining the yield and quality targets of hydroponics tomato while their contribution to possible minimization of environmental pollution. [ABSTRACT FROM AUTHOR]

Global challenges resulting from increased population and increased use of water and soil resources encourage researchers to focus on new compounds, such as nano-fertilizers. Hence, the present study aims to find out and compare the impact of foliar spray of two potassium (K) sources with the different formula, i.e. nano-chelated potassium and potassium nitrate, on olive oil yield and content over two successive years (2017–2018). During the bud-swelling stage, before blooming, the pit hardening stage, and shortly after the harvest of table olive, the fertilizers are used at the concentration of 1.84 (K1) and 2.45 (K2) g potassium nitrate, 3 (nano-K1) and 4 (nano-K2) g potassium nano-chelated, corresponding to 0.81 g (K1 and nano-K1) and 1.08 g (K2 and nano-K2) pure potassium per liter. The results show that fruit yield and characteristics are affected by k2 foliar application. High oil percentage is achieved by k1, which results in a low crop load and the highest leaf carbohydrate content in August. Traits, such as total phenol compound and antioxidant capacity of oil, are strongly enhanced under nano-K1 fertilizer, but quality characteristics of olive oil are relatively affected. Furthermore, nano-K1 treatment can positively affect fatty acid composition through the improvement of leaf mineral content rather than controlling tree. According to the results, fruit yield and traits are better under potassium nitrate (K2) treatment, and the quality of olive oil is more stable after nano-chelate potassium (nano-K1) foliar application. [ABSTRACT FROM AUTHOR]

In this study, the efficiency of fertilizers was improved by coating the fertilizers with a hydrogel formed by the polymerization of itaconic acid (IA), maleic acid (MA), acrylic acid (AA), and potassium persulfate (KPS) to form a synergistic fertilizer and improve its slow-release performance. The effect of synergistic fertilizers on the changes in soil nutrients in wheat fields was studied through field and soil column experiments using ordinary and commercial synergistic fertilizers as controls and different application rates of 'synergistic fertilizers as treatments. The results revealed that the alkali-hydrolyzed nitrogen (N) and total N contents were significantly higher in T1 than that in CK, and the treatments were ranked as T3 > T2 > T5 > T1 > CK > T4. The difference in the alkali-hydrolyzed N and total N contents between CK and T3 was significant. In terms of available phosphorus (P) and potassium (K) contents, the treatments were ranked as T1 > T4 > T2 > CK > T3 in all soil layers and T3 > T2 > T5 > T1 > CK > T4 in the soil column. The treatments were ranked as T4>CK>T3>T1>T2 in terms of soil organic matter (SOM) content. Compared with ordinary fertilizers, synergistic fertilizers could significantly increase the soil total N, alkali-hydrolyzed N, available P, and available K contents. Compared with ordinary slow-release fertilizers in the market, the effect of synergistic fertilizers is better in improving the use efficiency of fertilizers. By slowly releasing nutrients, synergistic fertilizers can continuously provide nutrients for the growth and development of wheat and improve the use efficiency of fertilizer. [ABSTRACT FROM AUTHOR]

A three-year field experiment was conducted to evaluate the effects of straw combined with potassium fertilizer on maize yield, potassium utilization efficiency and soil potassium balance. The study consisted of two straw treatments (S1: straw returning; S0: no straw returning) and five K levels (0,30,60,90,120 kg K ha−1). The results showed that compared to S0, the maize yield and available K content in S1 increased by 2.9%~6.2% and 19.3%~37.4%. The average of agronomy efficiency and surplus rate in S1 were 7.3%~35.4% and 24.8%~84.7% higher than S0 respectively, but the recovery efficiency, partial factor productivity under S0 and S1 were statistically identical. When the surplus rate is 0, the amount of potassium fertilizer required and the corresponding yield to maintain the soil K balance in S1 were 87.9 kg ha−1 and 12,424.6 kg ha−1. Compared to S0, S1 can decrease potassium fertilizer application rate by 10.2% while increasing maize yield by 3.5%. Overall, straw return combined with potassium fertilizer can improve maize yield and soil available potassium content, it can also reduce chemical fertilizer input while increasing fertilizer utilization efficiency, and play a positive role in keeping soil K balance simultaneously. [ABSTRACT FROM AUTHOR]

The present study was conducted during the 2019/2020 and 2020/2021 growing seasons at Shandaweel agricultural research station, Sohag governorate to study the individual and combined effect of three rates of rice straw biochar and four rates of N, P and K mineral fertilizers on the agronomic traits, nutrient contents in leaves and grains, protein and carbohydrates content in grains of wheat cultivar Misr 3 as well as on some soil properties. The experiment design was a split plot with three replications, whereby biochar treatments occupied the main plots at a rate of 0, 5 and 10 t ha-1, while the sub plots were devoted to mineral N, P and K fertilizers at a rate of 0, 50, 75 and 100% of the recommended dose. Results revealed that the combined application of 10 t ha-1 biochar and 100% N, P and K fertilizers treatment recorded the highest values for all the studied traits as well as improving the soil properties compared to other treatments. Furthermore, the addition of 10 t ha-1 biochar with 75% and 100% of N, P, and K fertilizers significantly improved grain yield by (11.13 and 18.80%) in the first season and by (7.69 and 16.62%) in the second season, respectively compared to the application of 100% of N, P and K fertilizers without biochar. In conclusion, biochar can be used to reduce using all chemical fertilizers (N, P, and K) by 25% as well as enhancing soil fertility and wheat productivity. [ABSTRACT FROM AUTHOR]

Soils of arid and semi-arid environments are characterized by scant moisture conditions, low clay and organic matter contents, low water holding capacity and low inherent fertility, and hence various management practices including foliar fertilization is essential. The present study aims at assessing the effect of integrated soil and foliar application of nitrogen, phosphorus, and potassium (NPK) fertilizers on growth, yield, and contents of some osmoprotectants, antioxidant, and nutritional status of Capsicum annuum (L.) in sandy soil under semi-arid condition. A pot experiment was conducted with five NPK application treatments: 100% added to the soil + 0% foliar spray, 75% soil + 25% foliar spray, 50% soil + 50% foliar spray, 25% soil + 75% foliar spray, and 0% soil + 100% foliar spray. The results of the study indicate that the integrated treatment of 50% soil + 50% foliar spray proved to be the best treatment compared with other treatments. This treatment significantly increased growth components (leaf area plant‒1, shoot fresh and dry weights) and yield (number of fruits plant‒1, average fruit weight, and fruits weight plant‒1), and the contents of soluble sugars, free proline, and nutrients (NPK); while significantly reduced the contents of ascorbate and glutathione compared to other treatments, including the control. The combined treatment of 75% soil + 25% foliar spray was the second-best treatment with respect to all tested parameters. The study concludes that the recommend integrated treatment of 50% soil + 50% foliar spray minimizes nutrient loss and achieves higher growth and yield of hot pepper plants under semi-arid condition. [ABSTRACT FROM AUTHOR]

Lop Nor Playa is the main salt-forming area in the Tarim Basin, which is rich in brine resources. There is a large amount of potassium fertilizer produced from potassium-rich brine in Lop Nor annually, which meets about half of the demands of China's agricultural potash, along with that produced in the Qaidam Basin. In order to investigate the distribution characteristics of potassium-bearing minerals and the origin of potassium-bearing salts in Lop Nor Playa, mineralogy and hydrogeochemistry studies were carried out. The results showed that there are a large number of polyhalite layers distributed in the Luobei Depression and Xinqing Platform. Brines with high content of K+ and Mg2+ have reactions with calcium sulfate minerals, generating secondary polyhalite layers. Carnallite layers are mainly distributed in subbasins along fault zones in all three mining areas with small size. Ca-Cl-type waters rise to the surface along fault zones and mix with ground water as soon as they appear on the ground, forming the deposits of carnallite and bischofite after evaporation. During the generation of potassic salts, fault zones, on the one hand, control the margin of mining areas and the distribution of polyhalite layers. On the other hand, they act as the migration and reaction space for salt spring water, providing large amounts of ore-forming elements such as Ca2+, K+, and Mg2+. This study provides a theoretical basis for the exploration of potassium-rich brine in the Lop Nor Basin. [ABSTRACT FROM AUTHOR]

Potassium (K) performs multiple essential functions in the plant, including enzyme activation and osmotic regulation. Citrus fruit quality gains considerable influence from potassium (K) fertilizer rate, application method, and sources used. The conducted field experiment assessed the impact and response of different levels of K applications on the quality and yield parameters of citrus fruit, determining a suitable time, stage, and K fertilizer dose for citrus trees. Comparing traditional K fertilizer, i.e., sulfate of potash (SOP), with new-generation potassium (NG-K) employed the use of foliar and soil (basal) applications. Treatments included (i) T1: Control (0 NPK), (ii) T2: Recommended NP and without K, (iii) T3: 500 g K as sulfate of potash (SOP) (basal), (iv) T4: New generation K (NGK) fertilizer @1.5% (foliar), and (v) T5: 400 g NG-K fertilizer (basal). Observations revealed that citrus trees responded positively in growth characteristics, including fruit quality and physiological attributes, under both foliar and basal K fertilizer applications of different K sources. Notably, NG-K fertilizer proved a better source of K, whether applied as a basal dose or foliar spray. For growth characteristics like the fresh weight of leaves and fruit mass, obtaining the highest values of 35.2 and 172 g, respectively, resulted when applying a basal dose of NG-K. On the other hand, maximum total sugar content (13 mg L-1) and juice content (40%) occurred under foliar-applied NG-K. Foliar application of K fertilizer proved to be more effective for better growth and fruit quality parameters than the basal application of SOP. [ABSTRACT FROM AUTHOR]

Nitrogen (N) fertilizer of the urea type is very commonly used in Indonesia. The demand for this fertilizer is expected to increase, so an alternative is needed as a complement. Ammonium chloride (NH4Cl) is a by-product produced in the soda ash industry. This compound contains 26% N, which can be an alternative source of N nutrients for plants. The level of the following element, namely chlorine (Cl), is relatively high, so it is a concern that might affect the plant growth. This field experiment aimed to evaluate the effect of the application of ammonium chloride combined with potash fertilizers on the growth, production, and uptake of N and Cl nutrients in sweet corn plants. The trial was designed in a randomized group with nine treatments of 0%, 100%, 150%, and 200% N, combined with potassium sources from KCl and K2SO4. As a comparison, the source of N is urea at a dose of 100% N is referred to as the standard N treatment. Parameters observed included plant height, the weight of corn cobs and corn stover, N and Cl nutrient uptakes in seeds, leaves, and stems. The results showed that the application of ammonium chloride combined with different K sources markedly affected plant height, cob and plant stover weight, and N and Cl uptakes of sweet corn compared to controls. Applying N-ammonium chloride with KCl and K2SO4 showed no significant effect in growth and yield compared to standard N. The N dose showed no significant effect on plant growth and yield compared to the standard N dose. [ABSTRACT FROM AUTHOR]

Background: Replenishing the lost nutrients through the use of various soil amendments is vital in order to maintain soil fertility for sustained productivity in jhumland. Integrated Nutrient Management, can boost the upland rice productivity in jhumland by building up the lost soil nutrients. Methods: The study was conducted to evaluate the impact of integrated nutrient management on growth and yield of upland paddy (Oryza sativa L.) in Lai-Lad, Jirang Block of Ri-Bhoi District, Meghalaya, India; during 2019 and 2020. Randomised block design with 12 treatments was applied for the trial with 3 replications. Result: Application of 100% recommended doses of fertilizers + farmyard manure + Azospirillum lipoferum + phosphorus solubilizing bacteria + potassium mobilizing bacteria + Glomus + zinc solubilizing bacteria (T10) significantly increased plant growth in both years of cultivation. Grain yield, harvest index and benefit cost ratio of upland paddy were at par among the treatments and were higher in 2nd cropping year. Integrated nutrient management could increase the growth characters, maintain sustained yield and economic profitability of upland paddy in hilly terrains of north-east India, under jhum cultivation. [ABSTRACT FROM AUTHOR]

Citrus is manually counted to estimate the yield. By using some innovative agricultural techniques yield and production can be increased. Numerous agricultural innovations have been introduced in recent years. Higher agricultural production, prediction, and reliable crop status information are more important than ever due to the expected growth of the human population. Agriculture has always been the foundation of human society. Current study was aimed to develop a reliable and meaningful information-gathering agricultural field based on image processing during 2020. Citrus yield can be increased in the initial stages by counting it with RGB and HSV-based images taken from an Android phone from various angles using machine learning techniques. Fertilizers such as potash, phosphorus, and nitrogen can then be utilized to boost yield. According to the findings, farmers can control and monitor citrus health production more efficiently and effectively by integrating machine learning with agriculture. The citrus calculation using the given technique compared with manually counted citrus, having difference of up to 5 to 10 citruses for a single plant per plot in a field. The proposed method produced excellent results under varying lighting conditions, leaf occlusion, and fruit overlap on photos taken at various distances from the orange trees. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to investigate the effects of balanced fertilization on the fertility and microbial community structure of Amaranthus tricolor L. inter-root soil, to provide a reference basis for shaping a fertile A. tricolor inter-root soil microenvironment and constructing a high-yielding and high-quality A. tricolor production technology system.【Method】Based on traditional and high-throughput sequencing techniques, the study analyzed the changes of soil fertility and microbial community structure in the inter-rhizosphere of A. tricolor under the conditions of blank control(CK),potassium deficiency fertilization(NP),nitrogen deficiency fertilization(PK),phosphorus deficiency fertilization(NK) and balanced fertilization[188.0,53.0 and 50.0 kg/hm² of nitrogen, phosphorus and potassium(NPK) fertilization, respectively].【Result】Application of different ratios of N,P and K fertilizers increased β-glucosidase, aminopeptidase and phosphatase activities in A. tricolor inter-root soil; Compared with the NPK treatment, the microbial biomass carbon(C),N and P contents of A. tricolor inter-root soil were generally lower in the non-balanced fertilizer treatment; All fertilizer treatments contributed to increase the bacterial diversity and richness of A. tricolor inter-root soil, but only the balanced fertilizer treatment increased the diversity and richness of fungi in the inter-root soil of A. tricolor. At the level of bacterial phylum classification, abundance percentage of the dominant bacterial phylum Proteobacteria, Acidobacteriota, Patescibacteria, Gemmatimonadota, Bacteroidota and Myxococcota in A. tricolor inter-rhizosphere soil in all fertilizer treatments increased, but that of Actinobacteriota and Chloroflexi decreased. At the taxonomic level of bacterial genera, fertilization not only obviously changed the abundance of bacterial genera at the taxonomic level of A. tricolor roots, but also enriched some specific dominant bacterial genera(unclassified＿o＿ Saccharimonadales,norank＿ f＿LWQ8 and Sphingomonas). At the fungal phylum taxonomic level, Ascomycota, Chytridiomycota, Mortierellomycota and unclassified＿ k＿ Fungi were the dominant fungi common to all fertilizer treatments; At the taxonomic level of fungal genera, Plectosphaerella,unclassified＿ f＿ Chytridiaceae,Gibellulopsis,Phialemonium,Mortierella,unclassified＿ k＿ Fungi and Myrothecium were the dominant fungal genera in the top 10 in terms of abundance in the different fertilizer treatments and missing from CK.【Conclusion】The application of different ratios of N,P and K fertilizers helped to improve the fertility of A. tricolor inter-roots soil and create a healthy soil environment, among which the balanced application(188.0,53.0 and 50.0 kg/hm2 of N,P and K fertilizers respectively) was the most effective in increasing the abundance and diversity of A. tricolor inter-root soil bacteria and fungi and improving the microenvironment of A. tricolor inter-root soil. It can be applied in the production of A. tricolor. [ABSTRACT FROM AUTHOR]

Potassium (K) is the most important element for fruit quality improvement. This study aimed at determining the best K fertilizer type that can promote grape growth and nutrient uptake. Specifically, four types of K fertilizers (complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate) were applied to grapevines grown in plastic pots, and then their effects on grape growth and nutrient uptake were explored. Results showed that the complex fertilizer and potassium nitrate treatments increased the biomass of the grapevine plants, whereas the other fertilizers had no significant effects on the biomass. Only the potassium nitrate treatment increased the contents of photosynthetic pigments in grapevine leaves. The complex fertilizer and potassium nitrate treatments increased the total N content in the grapevine plants to some extent, whereas the other fertilizer treatments decreased the total N content to some extent. It was also evident that all four K fertilizers increased the total P and K contents in the grapevine plants. Compared to the control, the complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate treatments increased the scion total P content by 20.18%, 9.77%, 12.52%, and 30.81%, respectively, and increased the scion total K content by 15.37%, 8.41%, 20.15%, and 26.48%, respectively. In addition, correlation and grey relational analyses showed that the rootstock stem total N content, rootstock root biomass, and soil alkali-hydrolyzable N concentration were the top three indicators most closely associated with the scion total N content, whereas the rootstock root total P content, soil available P concentration, and rootstock stem total P content were the top three indicators most closely associated with the scion total P content. Additionally, the rootstock root total K content, soil available K concentration, and rootstock root total P content were the top three indicators most closely associated with the scion total K content. Overall, the different K fertilizers can all promote the uptake of P and K by grapevine plants, and the potassium dihydrogen phosphate fertilizer is the best choice. [ABSTRACT FROM AUTHOR]

To prove the hypothesis that paddy rice utilizes soil nonexchangeable potassium (neK) and causes associated structural changes in clay minerals, K status and clay mineralogy of 22 surface soils from three paddy fields under long‐term fertilizer management for 51–93 years were investigated. Soil neK content was determined as the difference between 1 mol L−1 hot HNO3 extractable K and 1 mol L−1 ammonium acetate exchangeable K. Clay mineralogy was identified by X‐ray diffraction (XRD). The radiocesium interception potential (RIP), an index of frayed edge sites in the interlayer sites of 2:1 type clay minerals, was also determined. The neK contents under the ‐K and NPK treatments were considerably lower than those under the unfertilized treatment in all the fields, indicating the exploitation of soil neK by rice. XRD analysis of the clay samples revealed 7% shift from the 1.0 peak to 1.4 nm one under the ‐K treatment compared with the unfertilized one, and the amounts of neK were negatively correlated with those of RIP (p <.01), suggesting the expansion of interlayer spaces of the 2:1 type phyllosilicates such as mica due to the release of neK. In addition, the neK content positively correlated with K balance of the long‐term experiments (p <.05). The differences of neK between unfertilized K and ‐K treatments corresponded to 22–157 kg K ha−1, or 0.42–1.68 kg K ha−1 year−1. In conclusion, utilization of considerable amount of soil neK under K depleted conditions should be considered to establish sustainable K management for paddy rice. [ABSTRACT FROM AUTHOR]

Nutrient status of plant affects root exudates of plant. Little is known about effect of potassium status on root exudation. Objective of this study was to identify metabolites in rhizosphere soil of soybean under different potassium conditions. Two soybean cultivars (Satonohohoemi (SAT) and Tachinagaha (TAC)) were grown in soil culture under low (K0, without potassium fertilizer) and normal (K2, 0.42 g K kg−1) soil potassium status. Soil solutions were collected at 15 and 25 DAS. Metabolites in soil solution were detected by CE-TOF MS. Low potassium tolerance was higher in SAT than TAC. Shoot and root K concentration in SAT was lower in K0 than that in K2. Forty-seven metabolites were detected in rhizosphere soil solution of SAT, TAC and without plant. Low K condition increased 6 and 3 metabolites concentration in soil solution without plant and 2 and 4 metabolites concentration with SAT and 2 and 1 metabolites concentration with TAC, at 15 and 25 DAS, respectively. Low K condition decreased 1 and 1 metabolites concentration in soil solution without plant and 6 and 6 metabolites concentration with SAT and 0 and 2 metabolites concentration with TAC, at 15 and 25 DAS, respectively. Increased and decreased metabolites were different between SAT and TAC. These results suggest that K status affect metabolites in root exudate and rhizosphere microbes of soybean and there is cultivar difference in these metabolites. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Journal of Central China Normal University is the property of Huazhong Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Deep fertilization is effective for improving crop yield and fertilizer use efficiency. However, its impact on mechanized direct‐seeded rapeseed and the optimal fertilization depth are poorly understood. A field experiment was conducted to evaluate the fertilization depth effect on mechanized direct‐seeded rapeseed growth. Five treatments were designed: surface broadcast fertilizer, no fertilization, and fertilizer banded placement at soil depths of 5 (D5), 10 (D10), and 15 cm (D15). Results: Compared with surface broadcast fertilizer, deep fertilization generally increased seed yield and partial factor productivity by 11.0%, agronomic efficiency (AE) by 22.7%, and recovery efficiency (RE) by 79.2% due to the increase of root mass density (16.8%), plant height (8.6%), height of the first branch (10.6%), stem diameter (22.4%), shoot biomass (16.1%), and shoot nitrogen (35.7%), phosphorus (29.7%), and potassium (26.2%) uptake. D10 had the highest seed yield, oil yield, fertilizer use efficiency, and economic benefits at different fertilization depth treatments. Compared with D5 and D15 respectively, D10 increased seed yield by 5.4% and 46.0%, oil yield by 7.7% and 50.5%, partial factor productivity by 5.4% and 46.0%, AE by 9.0% and 99.5%, RE of nitrogen by 48.9% and 34.9%, RE of phosphorus by 83.1% and 38.0%, and RE of potassium by 57.5% and 32.5%. The economic benefits of D10 were CNY 867.31 ha−1 and CNY 4864.23 ha−1 higher than D5 and D15 respectively. Conclusion: Considering rapeseed growth and its economic benefits, this study shows that 10 cm is an appropriate placement depth with regard to mechanized direct‐seeded winter rapeseed production. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The direct aqueous mineral carbonation of wood combustion ash (WCA), which is a representative high-calcium waste from combustion process, was systematically investigated by varying complex operating conditions, including reaction time, liquid-to-solid ratio (L/S), CO2 concentration, and particle size. The WCA exhibited high CO2 sequestration characteristics with an optimal carbonation efficiency of 76.4%, corresponding to a CO2 sequestration capacity of 0.314 g CO2/g WCA. In addition to solid carbonates, dry residues from liquid products with high potassium contents are potential feedstocks for quality potash fertilizer. Modified shrinking core models based on diffusion-controlled mechanism were proposed to evaluate the carbonation process. The theoretical framework assumes a contracting interface mechanism where active CaO reacts with CO2 to form a product layer. The effective diffusion coefficient of CO2 through the product layer decreases over time, giving deficient carbonation efficiency. The newly proposed models corresponding to different geometrical dimensions provided more perfect fit to the experimental data when compared with the most commonly used kinetic equations. The low apparent activation energy of the carbonation reaction demonstrated the diffusion-controlled mechanism. This work is useful for improving the economics and feasibility of bioenergy carbon capture and storage (CCS) technology chain. [ABSTRACT FROM AUTHOR]

To clarify the distribution pattern and characteristics of straw and livestock manure in Sichuan Province in recent years and provide a scientific basis for the resource utilization of agricultural waste in Sichuan Province, this study discusses the potential and ways of recycling straw and livestock manure in each county and uses spatial analysis to study the distribution and aggregation areas of straw (rice, wheat, maize and rapeseed) and livestock manure (cattle, sheep, pig and poultry) resources in Sichuan Province, which is based on the county scale production of major crops yield and livestock output in Sichuan Province in 2018. The results were obtained that the total amount of collectable straw (rice, wheat, maize and rapeseed) in Sichuan Province in 2018 was 28 085.5 thousand tons, with the distribution showing the pattern of "one center, dense in the east and sparse in the west", and the straw types were mainly maize and rice. In 2018, the total amount of livestock manure in Sichuan Province was 81 620.2 thousand tons, with the distribution showing the pattern of "three centers, dense outside and sparse inside". Pig manure occupies the absolute dominant, accounting for 57.8%. In 2018, the fertilizer application of annual straw production in Sichuan Province could theoretically save 7.4% of nitrogen fertilizer and 5.0% of phosphate fertilizer input in this province, and the total potassium could meet the amount of potash fertilizer. Energy utilization of straw can be converted into 14.227 1 million tons of standard coal or 6.22×109 m³ biogas. In 2018, the total fertilizer utilization of livestock and poultry manure in Sichuan Province could save 42.6% of nitrogen fertilizer input, and the total phosphorus and total potassium in livestock and poultry manure could meet the consumption of phosphorus and potassium fertilizer in Sichuan Province. Energy utilization of livestock and poultry manure can be converted into 8.351 9 million tons of standard coal or 4.15×109 m³ biogas. There were 30, 40, and 48 straw hotspot counties in 99%, 95%, and 90% confidence intervals, respectively, with the amount of straw in the hotspot counties accounting for 39.4%, 49.5%, and 56.3% of the total amount of straw in the province, respectively. There were 23, 31, and 37 livestock manure hotspot counties, respectively, and the proportion of livestock manure in hotspot counties to the total amount of livestock and poultry manure in the province was 24.4%, 33.9%, and 38.8%, respectively. The Chengdu Plain and the hilly areas of eastern Sichuan have been the key areas for straw and livestock manure resources enrichment and recycling in Sichuan Province in recent years. The pure straw and livestock manure hotspot counties have their own emphases when selecting utilization patterns, and the 21 straw-livestock manure hot spots counties can consider the combination of planting and raising modes and implementation of multi-level and diversified utilization patterns. [ABSTRACT FROM AUTHOR]

Accurate and effective management of irrigation and fertilization is essential for efficient greenhouse strawberry production. Here, the effects of the combined application of water and potassium on strawberry growth were evaluated by experimenting with 12 treatments, including four transpiration (ETC)-based irrigation levels (W1: 100% ETC, W2: 85% ETC, W3: 70% ETC, and W4: 55% ETC) and three potassium levels according to the target yield (K1: 369.5 kg/hm², K2: 307.9 kg/hm², and K3: 246.3 kg/hm²). Various indexes of strawberry yield, fruit quality, water and fertilizer utilization efficiency, and soil nutrient residues were measured. Irrigation and potassium application had significant effects on strawberry production. Higher irrigation levels increased yield (Y), and moderate water and potassium application increased single fruit weight (SFW), water utilization efficiency (WUE), total soluble sugar (TSSC), and the sugar-acid ratio (SAR). While low-application of potassium increased the soluble protein content (SP), partial factor productivity of potassium (PFPK), and reduce nutrient residues in soil effectively. A comprehensive system for evaluating strawberry growth and its benefits to the soil environment was developed. The FAHP and CRITIC methods were used to calculate the subjective weight and objective weight of each index, respectively. The largest subjective weight was observed for Y (0.200), and the largest objective weight was observed for soil-available potassium (0.101). The final weight was determined using Game theory; Y had the highest weight (0.185), and free amino acids (FAA) had the lowest weight (0.047). Grey relational analysis (GRA) was used to evaluate the optimal irrigation and potassium scheme for accomplishing multiple objectives. The response of the comprehensive score of strawberries to irrigation and potassium exhibited a negative parabolic relationship, and the effect of irrigation was greater than the effect of potassium application. There was a significant interaction between irrigation and potassium application, and an irrigation amount of 2053-2525 m³/hm² with a potassium application rate of 288.1-334.2 kg/hm² was optimal for promoting strawberry yield, fruit quality, and efficiency and reducing soil nutrient residues. The results of this study provide new insights that could aid the development of sustainable approaches for enhancing agricultural production. [ABSTRACT FROM AUTHOR]

The extensive use of chemical fertilizers is responsible for numerous environmental problems including low food quality, soil degradation, and toxicity to beneficial living organisms in the soil. Nano-fertilizers (NFs) application may be a promising solution for combat these challenges. The current study focused on the efficiency of applying small amounts of NFs incorporated with conventional nitrogen, phosphorus, and potassium (NPK) fertilizers to reduce the quantities of conventional fertilizers (CFs) in lettuce cultivated in sandy soil. This study evaluated the effect of these incorporations on plant growth, yield, phytochemical accumulation, leaf nutrient, and leaf nitrate. A pot experiment was conducted during the winter seasons of 2020/2021 and 2021/2022 using the following treatments: CF100: 100% CFs, CF75NF25: 75% CFs + 25% NFs, CF50NF50: 50% CFs + 50% NFs, CF25NF75: 25% CFs + 75% NFs, and NF100: 100% NFs (=10% of CFs). Our findings displayed that the CF75NF25 and CF50NF50 treatments recorded the highest plant growth parameter values (plant length, root length, number of leaves, and fresh and dry biomass). The maximum of chlorophyll fluorescence measurements (photosystem II efficiency) were obtained in plants fertilized with CF75NF25, followed by CF50NF50 and CF100. The improvement ratios of photosynthetic pigments (Chlorophyll (Chl) a, b, and total) for CF75NF25 were 23.77, 50, and 23.72% in the first season and 10.10, 51.0, and 24.90% in the second season for Chl a, b, and total, respectively, as compared with the CF100 treatment. A similar tendency was observed for the CF50NF50 treatment. Generally, CF75NF25 significantly raised the content of total phenolic compounds (TPC), total flavonoid content (TFC), and antioxidant activity (AOA) in lettuce plants by 36.09, 47.82, and 40.16% in the first season and by 30.39, 37.53, and 32.43% in the second season, respectively, compared with CF100. In addition, the levels of leaf nutrient content and uptake of N, P, and K were significantly higher in plants fertilized with CF75NF25 compared to the other treatments, whereas CF25NF75 had the lowest values among the different treatments across both seasons for most of the tested traits. The nitrate content in lettuce leaves (NO3−) for both seasons was lower than the acceptable level for human consumption. These results indicate that incorporating a low concentration of NFs into CFs could be a promising strategy to reduce the amount of CFs to 75% or 50% of lettuce NPK requirements without significant adverse effects on the growth and productivity of lettuce plants cultivated in sandy soil. [ABSTRACT FROM AUTHOR]

To clarify the preference of female and male plants of Fraxinus mandshurica for nutrient absorption will help to carry out precise fertilization of female and male plants, improve fertilization efficiency, and promote flowering and fruiting. This study took the female and male plants of F. mandshurica mature plantation as the objects, and carried out a complete test of three factors and three levels of nitrogen, phosphorus and potassium. Nitrogen fertilizer was set at three levels (0. 15、0. 30、0. 45 g / L), phosphorus fertilizer was set at three levels (0. 3、0. 6、0. 9 g / L), and potassium fertilizer was set at three levels (0. 2、0. 4、0. 6 g / L), a total of 27 treatments. The net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, relative chlorophyll content, leaf area and leaf nutrient content of leaves were measured at the second month after fertilization, and the correlation coefficients between various variables were discussed. The results showed that the mixed fertilization of nitrogen, phosphorus and potassium could promote the improvement of leaf functional traits of male and female F. mandshurica in different degrees. Except for intercellular CO2 concentration, leaf area and leaf phosphorus content, the maximum values of other indicators appeared in N3P2K2(female) and N2P3K3 (male) treatments, which were significantly higher than the control (P<0. 05). Under the same fertilization treatment, the male and female plants of F. mandshurica showed significant gender differences in the measured indicators. The N ∶P ranged from 8. 62 to 14. 08 and 7. 91 to 12. 80, the N ∶K ranged from 2. 33 to 4. 32 and 2. 47 to 4. 22, and the K ∶P ranged from 2. 67 to 4. 36 and 2. 75 to 3. 91, respectively. The mass fraction of nitrogen, phosphorus and potassium in leaves was negatively correlated with intercellular CO2 concentration (P<0. 05), and positively correlated with other physiological indexes (P<0. 01). The above results showed that the female plant of F. mandshurica under N3P2K2 and the male plant under N2P3K3 treatment had the best effect on the functional properties of its leaves. The main limiting element affecting the leaf function of F. mandshurica was N, and nitrogen fertilizer can be appropriately increased in forest land management. [ABSTRACT FROM AUTHOR]

French lavender (Lavandula dentata L.) is an ornamental, aromatic and medicinal plant. Potassium (K) is an essential macronutrient for plants and its complementation is a routine practice in crops in weathered soils. The most used source of potassium in Brazil is potassium chloride (KCl), which is often questioned by the presence of the Cl- ion. This study tested the performance of L. dentata plants grown under five levels (0, 50, 100, 200 and 300 mg.dm−3) of K supplied from: KCl and potassium sulfate (K2SO4). Rooted stem cuttings were transplanted in pots, in a greenhouse, with a random arrangement of blocks in a double factorial scheme. At the full blooming, plants were collected and evaluated for morphological characteristics. After, analyzes of the shoot mineral nutrients contents were carried out. The material was also used for the essential oils extractions. The only plant morphological characteristic that showed influence of the treatments was the number of inflorescences, where the plants fertilized with KCl showed superior results, being possible to calculate the maximum flower spikes production when applied an estimated level of 230 mg.dm−3 of K, as KCl. Among the contents of 14 nutrients evaluated, plants grown under KCl fertilizer showed changes in 12 nutrients contents, while plants from K2SO4 treatments showed only six altered nutritional contents. The essential oil yield was higher when K2SO4 was applied, with the maximum calculated yield (1.44%) achieved when the estimated level of 206 mg.dm−3 of K is applied (as K2SO4). [ABSTRACT FROM AUTHOR]

The dual role of nutrient uptake by plant roots and leaves is one of the main advantages of sprinkler fertigation, while an improper solution concentration suppresses plant physiology and even causes foliar burns. To explore the suitable solution concentrations of nitrogenous fertilizer, phosphate fertilizer and potassium fertilizer, field experiments were conducted at two sites in the North China Plain during the 2019 and 2021 growing seasons of summer maize. The foliar relative chlorophyll content (SPAD), foliar light energy conversion capacity (Fv/F0) and maximum light energy conversion efficiency (Fv/Fm) prior to and after fertilizer solution spraying were measured and compared. In the experiments, six urea concentrations (0.10 − 3.20%), eight monoammonium phosphate concentrations (0.03 − 4.80%) and seven potassium sulfate concentrations (0.10 − 4.80%) were tested during the jointing stage (V6), flare opening stage (V12), heading stage (VT) and filling stage (R2) of summer maize. The results showed that after spraying fertilizer solution, the spatiotemporal variability in Fv/F0 reached moderate from the weak spatiotemporal variability observed prior to spraying. The SPAD values reached moderate from the weak spatiotemporal variability only after spraying nitrogen fertilizer from V6 to VT and after spraying potassium fertilizer from V12 to R2. All the changes in the index variability suggested a great influence of foliar nutrient absorption on plant physiology. Averaged over 5 days following nutrient spraying during the whole season, the average increments synthesized by SPAD, Fv/F0 and Fv/Fm were 1.60, 1.33, and 1.21 times, and the average reductions were 0.62, 0.78 and 0.62 times, respectively. Depending on the fertilizer type and spraying opportunity, the influence of the fertilizer solution on plant physiology changed greatly. To maximize the relative chlorophyll content and photosynthetic capacity of foliar plants resulting from fertilizer solution spraying, the recommended urea solutions were 0.10 − 0.80%, 0.40%, 0.25 − 0.40% and 0.25 − 0.40% during the V6, V12, VT and R2 stages, respectively. For monoammonium phosphate, the suggested concentrations were 0.06 − 0.15%, 0.06 − 0.15%, 0.03 − 0.40% and 0.03 − 0.80%, respectively. Spraying potassium sulfate at a concentration of 0.10 − 0.40% during the V12 and VT stages would benefit plant growth. [ABSTRACT FROM AUTHOR]

Water-saving irrigation area has increased steadily in China, with the rapid development of mechanized farming and land transfer. Among them, drip irrigation can greatly contribute to agricultural water-saving and high efficiency in northwest and northeast China. Drip irrigation can directly transport the fertilizer with water to the root zone of crops, and then effectively improve the fertilizer utilization rate. But the improper fertilization can lead to emitter blockage and a decrease in fertilization uniformity, resulting in crop yield loss. It is a high demand to implement chemical blockage in the field, due to the high requirements. In this study, the clogging performance was tested using commonly-used emitters (Inlaid cylindrical labyrinth emitter, E1; Inlaid patch labyrinth emitter, E2; Flanking labyrinth emitter, E3) with the Urea (UREA), Sulphate of potassium (SOP), Muriate of potash (MOP), Monoammonium phosphate (MAP), Diammonium phosphate (DAP) under different concentrations (0, 0.4, 0.8, 1.0, 1.2 g/L). The morphology and composition of clogged substances inside the emitter were analyzed to combine with field emission scanning electron microscopy (FESEM), surface energy spectrum analysis (EDS), and X-ray diffractometer (XRD). The sensitive fertilizer and emitter were then determined for the reasonable suggestions of fertigation. A theoretical basis was provided to inhibit the chemical clogging by an indoor simulated irrigation acceleration experiment. The results showed that there were different effects of fertilizers on the hydraulic properties and clog development of drip irrigation tape. There was no influence of potassium fertilizer on the hydraulic properties of E1 and E2, but little effect was found on the clogging degree of E3. Little influence was found in the mono-ammonium phosphate on the hydraulic performance of E1, but there was a slight blockage to E2 and E3. Diammonium phosphate was irrelated to the hydraulic performance of E1, but there was a slight blockage to E3, and a serious blockage to E2. Urea did not affect E1 and E2, but there was a clogging risk to E3. Therefore, the UREA and DAP were recommended to be avoided in irrigation. The uniformity increased with the increase of urea concentration in the range of 0.4-0.8 g/L, while the uniformity decreased in the range of 1.0-1.2 g/L. By contrast, the relative average discharge and irrigation uniformity of E3 decreased with the increase of irrigation times, whereas, the decrease rate increased with the increase of fertilizer concentration, as the diammonium phosphate concentration increased. Thus, the fertilization concentration of diammonium phosphate should not exceed 1.2 g/L. The local bulges on the surface of clogged substances were gradually higher than the initial state in the process of irrigation. The attached fouling was thinner, whereas, there was an increase in the scaly structures and the surface roughness. After irrigation, the attached fouling layer thickened, the surface roughness developed completely, and the structure was encrypted gradually from wide-scale structure to fine-scale structure. The dry weight of the clogged substance increased with the increase in the irrigation time. There was the consistency with the trend that the relative average discharge and uniformity of the emitter decreased with the increase in irrigation times. The more chemical fouling increased, the less the effect of water shear force on it, as the concentration of fertilizer solution increased. It is necessary to further improve the filtration efficiency of irrigation water, and reduce the content of suspended solids in irrigation water. A reasonable and perfect evaluation of water quality can also be conducted to reduce the occurrence of chemical blockage in fertigation systems. [ABSTRACT FROM AUTHOR]

Potassium is one of the principal macronutrients required by all plants, but its mobility is restricted between soil compartments. Numerous studies have shown that Plant Growth Promoting Bacteria (PGPB) can facilitate nutrient uptake. The present work examined the effects of the PGPB (Bacillus megaterium) on rice plants subjected to potassium deprivation. To study only direct effects of B. megaterium , we first checked its lack of capacity to solubilize soil K. Rice plants were provided with 1.5 mM K (100%) or 0.015 mM K (1%) and growth related parameters, nutrient concentrations and gene expression of K+ transporters were determined. After two weeks, the 1% K treatment reduced growth of non-inoculated plants by about 50% compared with the 100% K treatment. However, there was no effect of reduced K nutrition on growth of inoculated plants. The reduction in growth in non-inoculated plants was accompanied by a similar reduction in K+ concentration in both roots and leaves and an overall 80% reduction of the plant potassium concentrations. In inoculated plants a 50% reduction occurred only in leaves. The expression of the K+ transporters HKT1;1 , 1;2 , 1;5 , 2;2 , 2;3 and 2;4 was up-regulated by the inoculation of B. megaterium under K deprivation conditions, explaining their higher K tissue concentrations and growth. Thus, the bacterial strain improved plant potassium nutrition without affecting K+ availability in the soil. The results demonstrate the potential of this bacteria for using as a biofertilizer to reduce the amount of potassium fertilizers to be applied in the field. • Interaction between rice and B. megaterium increasing biomass and nutrient uptake under K+ starvation conditions. • B. megaterium up-regulates HKT and HAK genes K+ transporters in Oryza sativa roots. • B. megaterium affects K+ uptake not by solubilizing it but changing K+ transporters expression. [ABSTRACT FROM AUTHOR]

Compared with the standard method of manual fertilizer broadcasting (MFB), mechanized hill-drilling direct-seeding with deep application of slow-release nitrogen fertilizer (MHDDF) is an efficient method to integrate both fertilization and seeding. However, there are few studies that combine the use of slow-release fertilizer with MHDDF. We sought to explore the combined effect of MHDDF with slow-release fertilizer on rice yield and nitrogen, phosphorus, and potassium utilization, compared to MFB. We compared three different MHDDF methods (D30: 450 kg ha−1, D40: 600 kg ha−1, D50: 750 kg ha−1), with one MFB method (B50: 750 kg ha−1), and one control (CK: 0 kg ha−1). We found that the yield of all MHDDF method was higher than that of both the MFB method. Yield was the highest in the D50 treatment and was 14.14–46.03% higher than that in B50 treatment. Biomass accumulation, nutrient accumulation, and nutrient use efficiency were similarly higher in MHDDF method than both MFB and CK. Compared to B50, the D50 treatment increased nitrogen recovery efficiency by 170.53–231.50%, phosphorus recovery efficiency by 480.00–724.25%, and potassium recovery efficiency by 201.55–169.59%. Overall, we found that combining MHDDF with slow-release fertilizer was an effective method to increase rice yield and nutrient use efficiency compared with MFB. [ABSTRACT FROM AUTHOR]

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Orchard cultural practices, i.e., irrigation, fertilizer, and fruit thinning, are crucially encompassed to enhance fruit yield and quality. Appropriate irrigation and fertilizer inputs improve plant growth and fruit quality, but their overuse leads to the degradation of the ecosystem and water quality, and other biological concerns. Potassium fertilizer improves fruit sugar and flavor and accelerates fruit ripening. Bunch thinning also significantly reduces the crop burden and improves the physicochemical characteristics of the fruit. Therefore, the present study aims to appraise the combined impact of irrigation, sulfate of potash (SOP) fertilizer, and fruit bunch thinning practices on fruit yield and quality of date palm cv. Sukary under the agro-climatic condition of the Al-Qassim (Buraydah) region, Kingdom of Saudi Arabia. To achieve these objectives, four irrigation levels (80, 100, 120, and 140% of crop evapotranspiration (ETc), three SOP fertilizer doses (2.5, 5, and 7.5 kg palm−1), and three fruit bunch thinning levels (8, 10, and 12 bunches palm−1) were applied. The effects of these factors were determined on fruit bunch traits, physicochemical fruit characteristics, fruit texture profile, fruit color parameters, fruit skin separation disorder, fruit grading, and yield attributes. The findings of the present study showed that the lowest (80% ETc) and highest (140% ETc) irrigation water levels, lowest SOP fertilizer dose (2.5 kg palm−1), and retaining the highest number of fruit bunch per tree (12 bunches) had a negative effect on most yield and quality attributes of date palm cv. Sukary. However, maintaining the date palm water requirement at 100 and 120% ETc, applying SOP fertilizer doses at 5 and 7.5 kg palm−1, and retaining 8–10 fruit bunches per palm had significantly positive effects on the fruit yield and quality characteristics. Therefore, it is concluded that applying 100% ETc irrigation water combined with a 5 kg palm−1 SOP fertilizer dose and maintaining 8–10 fruit bunches per palm is more equitable than other treatment combinations. [ABSTRACT FROM AUTHOR]

Barley (Hordeum vulgare, L.) is the fourth most important cereal crop in the world. Salinity decreases the productivity of plants grown under salinity conditions. It leads to deficiency and limited absorption of water and nutrients, ionic stress, oxidative stress, and osmotic imbalance. In saline soil, a field experiment was conducted to verify the effects of nine combinations among three levels of bio-fertilizers, i.e., control (without), arbuscular mycorrhizal fungi (AMF), and phosphate solubilizing bacteria (PSB), as well as three levels of phosphorus fertilizer recommended dose (RDP) on barley yield, its components and nutrients uptake, to evaluate the useful influences of these combinations to improve P management under salinity stress related to yield and its components as well as N, P, and K uptake in barley. Findings revealed that the combination AMF + 100% RDP improved plant height, length of spike, spikes weight, number of spikes plant−1, weight of 1000-grain, straw yield, grain yield, uptake of nitrogen (N), phosphorus (P), potassium (K) in grain and uptake of nitrogen (N), phosphorus (P), potassium (K) in straw by 19.76, 33.21, 40.08, 33.76, 14.82, 24.95, 47.52, 104.54, 213.47, 168.24, 124.30, 183.59, and 160.84% in the first season, respectively. Meanwhile, the increase was 19.86, 29.73, 40.47, 39.94, 14.92, 24.95, 47.94, 104.73, 213.33, 168.64, 124.47, 183.86, and 161.09% in the second season, respectively. AMF showed greater efficiency and effectiveness compared to PSB in improving yield and its components for all studied traits. The results of principle component analysis indicated that all combinations except AMF + zero% RDP, PSB + zero% RDP, control + zero% RDP, and control + 66% RDP showed high scores on positive PC1, where all studied traits were high. Therefore, it is recommended to inoculate the soil with AMF or PSB with the addition of phosphate fertilizer at the recommended dose under salinity conditions, i.e., AMF + 100% RDP (T1) or AMF + 66% RDP (T2) or PSB + 100% RDP (T4). The use of bio-fertilizers has increased plant tolerance to salt stress, and this was evident from the increase in different traits with the use of treatments that include bio-fertilizers. [ABSTRACT FROM AUTHOR]

Chemical potassium (K) fertilizer plays a crucial role in improving crop productivity, yet its production and application also result in environmental issues including greenhouse gas emission and atmospheric pollution emissions. In addition, the abandon or open burning of crop straw not only causes the wasting of resource, but also creates environmental problems. On-present studies recognize the importance of the substitution of straw resource utilization for chemical K fertilizer, yet whether such action can effectively mitigate the emissions of greenhouse gas and pollutants remains unclear. In this study, we examine the effects of substituting straw for chemical K fertilizer on the emissions of greenhouse gas and pollutants and the associated direct and damage cost implications in China at the provincial level. Results showed that the useable straw contributed 2750 Gg of K from 2000 to 2009 and 3567 Gg from 2010 to 2017, equaling 121% and 57.3% of chemical K fertilizer, respectively. Chemical K fertilizer substitution with straw can also reduce annual emissions of greenhouse gases, ammonia, nitrogen oxide, and fine particulate matter by 664 Gg, 18.5 Gg, 10.7 Gg, and 1.48 Gg, respectively. The average abatement cost reached 4790 million USD during 2000–2009 and 3898 million USD during 2010–2017, respectively. And the mitigation potential of the emissions of greenhouse gas and pollutants and average abatement cost showed a large spatial heterogeneity at the provincial level. Overall, replacing chemical K fertilizer with straw is an efficient strategy to reduce environmental risk and utilize agricultural waste. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Journal of Agricultural Sciences (SJAS) is the property of Beni Suef University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)