Effect of NPK fertilization on the chemical properties and bioactive compounds of the cabezona pineapple fruit

Objective: To evaluate the effect of NPK fertilization on the chemical properties and bioactive compounds of the cabezona pineapple fruit. Design/methodology/approach: 15 NPK fertilization treatments were evaluated and carried out in the field in a random complete block design with four repetitions per treatment. At the end of the crop cycle, we determined the pH, °Brix and citric acid % of the fruits that were harvested, following the methodology established in NMX-FF-028 and 011. The pH of the juice was measured directly using a potentiometer. Ascorbic acid was measured with a SIGMA-ALDRICH® kit, the total polyphenol contents were determined following the methodology of De la Cruz-Ricardez et al. (2020), while total flavonoid contents were measured following a modified version of the methodology proposed by Hossain et al. (2011). Results: The mean values for °Brix, citric acid %, and pH were 7.3, 7.1 and 3.4 respectively, without significant differences between treatments. A highly significant difference in the concentration of ascorbic acid was observed between treatments; treatment three had the highest concentration (19.4 mg 100 g-1 FF). There were no significant differences between the fertilization treatments and the control, regarding total polyphenol content (41.34 mg 100 g-1 FF) and flavonoids (1.6 mg 100 g-1 FF) concentrations. Study limitations/implications: The ripening degree of the pineapple fruit directly influences the chemical properties and the concentration of bioactive compounds. Findings/conclusions: NPK fertilization had no effect on °Brix and pH. The citric acid percentage and the total polyphenol content increased as the doses of P2O5 increased. The ascorbic acid concentration and total flavonoid content are not affected by the NPK fertilization dose.

Sorghum cultivation of the ratoon system for increased yields in dry land

Planting sorghum twice a year on dry land is constrained by the short duration of rainfall, so it requires technology to increase yields with the ratoon cropping system. The research was carried out in Agricultural Technology Research and Assessment Installation of Bajeng, Gowa, South Sulawesi from March to October 2019. The superior genotypes of sorghum were planted on marginal land as the main crop with a spacing of 75 cm x 20 cm (66,666 plants/ha). The ratoon plant used a split-split plot design. The main plot consisted of two mulches: M1=no mulch + 50% dose of main crop fertilization and M2=sorghum stover mulch + biodecomposer 1kg/ha without NPK fertilizer. The sub-plots consisted of 2 populations: P1=population of 66,666 plants/ha (1 shoot/hole), P2=133,332 ratoon plants/ha (2 shoots per hole). The sub-sub-plots consisted of 5 (five) genotypes/varieties of sorghum: V1=Numbu, V2=No.58-1, V3=No. 86.1, V4=No.103-1 and V5=No. 113-1, so that 20 treatment combinations were obtained with 3 replications. The results showed that to obtain high grain yield in ratoon cultivation in dry land, NPK fertilization (150-100-50)/ha is still necessary. The increase in population density of ratoon from 66,666 to 133,333 plants/ha significantly affected the increase in grain yield. Sorghum genotype No. 58-1, No. 86-1, No. 103-1 and No. 113-1 is technically and economically feasible to be developed in the cultivation of the double harvest ratoon system with the profit (Rp 10,989,000-12,247,500/ha) from the cultivation of sorghum once the main crop (Rp 4,003,000-4,856,000). The R/C value is 2.00-2.10 and the MBCR value is 2.27-2.38.

Effectiveness and recommendation of NPK-compound fertilization on maize

The development of maize plants in the wet tropics was experiencing problems due to a lack of nutrients, especially N, P, and K, so that to get optimal yield, additional nutrients are needed through NPK fertilization. This study aims to determine the effectiveness of fertilizers and provide recommendations for the appropriate dose of compound NPK fertilization (formulation 15:15:15, 20:10,10, and 15:8:10) to increase production, farming efficiency, and income of maize farmers. This research was conducted at the Experimental Farm of Indonesian cereal Research Institute, Maros from June until October 2020. This research was arranged in randomized block design with three replication. The treatment consists of five NPK- compound fertilizers with two doses of NPK+ urea combination. The comparisons were Urea (control) and Urea + SP36+KCl (standard). The results of this research were all formulations of NPK compound fertilizers (15:15:15, 20:10:10, and 15:8:10) deserve to be recommended for maize. Recommendations for applying NPK 15:15:15 compound fertilizer to maize plants are 450 kg/ha combined with 250 kg urea/ha with a yield probability of 12 t/ha. The recommendation for applying 20:10:10 NPK compound fertilizer to maize was 350 kg/ha + 200 kg urea with a yield probability of ±11 t/ha. The recommendation for giving NPK 15:8:10 compound fertilizer for maize was 450 kg/ha combined with 250 kg urea/ha with a yield probability of 11 t/ha.

Analysis of the Economic Potential Trough Biochar Use for Soybean Production in Poland

Soybean (Glycine max L.) is one of the most important crops grown globally. Biochar has been proposed as an alternative to aid sustainable soybean production. However, comprehensive studies that include both the economic aspects of soybean production and biochar are scarce. Poland, with an economy largely based on agriculture, is an interesting case to investigate the cost-effectiveness of using biochar in soybean production. We show that the use of biochar at rates of 40, 60 and 80 t/ha is unprofitable compared with a traditional soil amendment, such as NPK fertilization. The breakeven price for biochar to be economically viable should be USD 39.22, USD 38.29 and USD 23.53 for 40, 60 and 80 Mg/ha biochar, respectively, while the cost of biochar used for this experiment was USD 85.33. The payback period for doses of 40 and 60 Mg/ha was estimated to be three years. With a carbon sequestration subsidy of USD 30 per ton of CO2, the use of biochar may be profitable in the first year of soybean production. This is the first comprehensive economic analysis of the use of biochar in soybean production in Poland and one of the few published worldwide.

Soil Bacteria to Regulate Phoebe bournei Seedling Growth and Sustainable Soil Utilization under NPK Fertilization

Soil bacteria play a key role in the plant–soil system and can regulate the growth of Phoebe bournei seedlings under fertilization. However, there are few reports on how soil bacteria respond to fertilization and regulate seedling growth. This study adopted the “3414” field fertilization experiment, combined with soil microbial sequencing, nutrient contents, and biomass measurement, to explore the changes of soil chemical properties and bacterial structure under different NPK fertilization conditions and to establish the coupling relationship between soil bacteria, soil nutrients, and plant growth. The results showed that NPK fertilization decreased soil pH; increased soil N, P, and K content; reduced bacterial diversity and abundance; promoted the growth of dominant bacterial species; and enhanced Phoebe bournei seedlings’ soil N, P, and K elements. NPK fertilization promoted Proteobacteria growth, especially of three genera (Methylobacterium, Sphingobium, and Acinetobacter) and Actinobacteria, while it decreased Acidobacteria and Chloroflexi. By reducing the ratio of N to K and increasing P, NPK fertilization can slow soil acidification, promote bacterial reproduction, maintain P. bournei seedlings’ soil ecological stability, and balance the seedlings’ growth and sustainable soil utilization. AD3, Pseudomonas, and Rhodanobacter can be used as the marker species for N, P, and K fertilization, respectively, while Methylobacterium, Brevundimonas, Acinetobacter, and Sphingobium can be used as indicator species for soil pH and soil N, P, and K content changes, respectively. These results provided a theoretical basis and technical guidance for the effective fertilization and cultivation of robust P. bournei seedlings.

OPTIMALISASI PEMUPUKAN DI LAHAN GAMBUT

Increasing the productivity of peatlands can be done by applying the right fertilization system. The purpose of this study was to determine the appropriate dose of NPK fertilization in intercropping red chili and shallots on peat soil. This research was conducted at the Laboratory and Experimental Garden of the Faculty of Agriculture, Indragiri Islamic University. The study took place from August to December 2020. The study was carried out using a Completely Randomized Design (CRD) with 3 replications. , N2 (500 kg/ha), N3 (750 kg/ha) in red chilies and shallots. The results showed that treatment with a dose of 500 kg/ha of NPK fertilizer in an intercropping system of chili with shallots on peat soil gave the best growth and yield of shallots. Treatment dose of 250 kg/ha NPK fertilizer gave the best red chili fruit production

Productivity Responses of Buckwheat IPR 91 Baili to Different Doses of NPK in Brazil

Buckwheat (Fagopyrum esculentum Moench) is a prominent crop in today’s agriculture. However, information about its behavior at different doses of NPK fertilization is scarce. The aim of this work was to determine the ideal fertilizer dose for the buckwheat cultivar IPR 91 Baili by establishing the dose-response curve. Two experiments were carried out (greenhouse and in the field). The treatments consisted of different doses of NPK (0, 100, 200, 300, 400 and 500 kg ha-1). After the crop cycle, productivity was obtained. There was a statistical difference between the treatments and the control, in both experiments. The lowest yields were obtained in the controls, 2,301.156 and 2,262.500 kg ha-1, and the highest 4,052.023 and 4,027.778 kg ha-1 at the dose of 500 kg ha-1, in the greenhouse and in the field, respectively. There was no statistical difference between the NPK doses for the yield obtained. The rural producer must use the lowest dose (100 kg ha-1). Future experiments are needed to evaluate the culture response to doses below 100 kg ha-1.

Coconut fiber biochar alters physical and chemical properties in sandy soils

This work aimed to characterize the biochar produced from residues of coconut fruit and to evaluate how it might beneficially alter the retention capacity of water and nutrients in soils with a sandy texture. The biochar was produced in a retort furnace and later analyzed to determine its chemical and physical characteristics. Experiments to analyze the retention potential of the biochar for water and nutrients were performed in PVC columns filled to a 400 mm depth, with the upper 300 mm receiving treatments that consisted of 0, 1, 2, 3, 4, and 5% (p p-1) biochar mixed with soil. For the nutrient retention experiment, in addition to the biochar concentrations, the treatments received the same NPK fertilization. The experiments were performed in a completely randomized design with four replications. The water retention in the upper 300 mm, as well as the pH, effective cation exchange capacity (ECEC) of the substrate, base saturation, and concentrations of P and K, increased with increasing biochar concentration. Coconut biochar demonstrated potential for increasing water retention and improving nutrient retention in sandy soils.