Fertilization of two genetic groups of Pinus patula Schiede ex Schltdl. & Cham. in a four-year progeny trial

Introduction: Genetic improvement and nutritional management are used to increase productive capacity. Objective: To analyze the effect of traditional and controlled-release fertilizers, as well as the way to define the doses (technically or empirically), on growth of 20 tree families of Pinus patulaSchiede ex Schltdl. & Cham. Materials and methods: Four fertilization treatments were applied: 1) control; 2) “technical”, based on foliar analysis; 3) controlled release (18-6-12 + 2CaO + 3.5 Mg + 2.1 Si + microelements); and 4) mixture of agricultural fertilizers in nutrient concentrations similar to the controlled-release treatment. Height, diameter, biomass index, number of whorls, leaf mass, and growth initiation and cessation were evaluated in a group of 10 superior and 10 inferior three-year old families in Chignahuapan, Puebla. Data were analyzed with the MIXED procedure of SAS. Results and discussion: Trees showed no significant differences in growth, biomass production and growth initiation by fertilization effect, but showed significant differences by genetic quality (P ≤ 0.05). The genotype*fertilization interaction was significant; after one year of controlled-release fertilizer application, inferior genotypes had the highest values of relative rates of biomass production, diameter at root collar and height. Conclusions: Controlled-release fertilizers at appropriate doses and environmental conditions are a viable option to promote growth of young P. patula trees in the field.

Co-fertilization of sulfur and struvite-phosphorus in a slow-release fertilizer improves soybean cultivation

In face of the alarming world population growth predictions and its threat to food security, the development of sustainable fertilizer alternatives is urgent. Moreover, fertilizer performance should be assessed not only in terms of yield but also root system development, as it impacts soil fertility and crop productivity. Fertilizers containing a polysulfide matrix (PS) with dispersed struvite (St) were studied for S and P nutrition due to their controlled-release behavior. Soybean cultivation with St/PS composites provided superior biomass compared to a reference of triple superphosphate (TSP) with ammonium sulfate (AS), with up to 3 and 10 times higher mass of shoots and roots, respectively. Additionally, St/PS achieved a 22% sulfur use efficiency against only 8% from TSP/AS. Root system architectural changes may explain these results, with higher proliferation of second order lateral roots in response to struvite ongoing P delivery. Overall, the composites showed great potential as efficient controlled-release fertilizers for enhanced soybean productivity.

Plant quality index of caracolillo (Ormosia macrocalyx Ducke), in nursery stage with controlled release fertilizers

Objective: To evaluate, in a nursery, the effect of two controlled release fertilizers in three concentrations on the growth components and quality index in caracolillo seedlings. Design/Methodology/Approach: A factorial arrangement (2 x 3) housed in a completely randomized design was used, with seven treatments and twelve repetitions. For three months, the growth of caracolillo plants maintained in 310 cm3 polyethylene tubes, with a substrate of peat moss, vermiculite, agrolite and soil (2:1:1:1), plus controlled release fertilizer (CRF) Basacote® 9M (16-8-12) and Multicote® 12M (18-6-12), in three doses each: 10 (low), 20 (medium) and 30 kg m-3 (high), in addition to a control without conventional fertilization (CF) 17N-17P-17K in doses of 10 kg m-3. The variables height, diameter, leaf number, robustness index (RI), aerial/root dry biomass ratio (ADB/RDB R) and Dickson’s quality index (DQI) were measured. The means were compared by Tukey’s test at a 5% confidence level. Results: Basacote® and Multicote® fertilizers in low doses allowed an adequate growth and development in caracolillo plants, which was reflected in the variables height, diameter and number of leaves. The RI and DQI indices presented values within the normal ranges, while those of ADB/RDB R were rather low, but in the three cases there were no statistical differences. Study Limitations/Implications: Based on the results obtained, it is recommended to continue monitoring the studied plants in the field, which would allow adjustments in the initial fertilization doses. Findings/Conclusions: The low doses (10 kg m-3) of the controlled release fertilizers Basacote® and Multicote® showed the best results in the growth and development of caracolillo in the nursery stage, but the RI, ADB/RDB R and DQI indices did not present statistical differences.

Innovative Formulations of Phosphate Glasses as Controlled-Release Fertilizers to Improve Tomato Crop Growth, Yield and Fruit Quality

Three phosphate glass compositions, VF1, VF2, and VF3, containing macro and micronutrients with different [K2O/(CaO+MgO)] ratio, were formulated to be used as controlled release fertilizers for tomato crop, depending on their chemical durability in water and their propriety with respect to the standards of controlled-release fertilizers. This study investigated the influence of [K2O/(CaO+MgO)] ratio variation on glass properties. For this, the elaborated glasses have undergone a chemical characterization using inductively coupled plasma atomic emission spectroscopy, a thermal characterization using differential thermal analysis, a physicochemical characterization based on density and molar volume measurements, and a structural characterization using Raman spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. In addition, the chemical durability was determined by measuring the percentage of weight loss and the pH. Results revealed that the glass structure and composition have the mean role in controlling the release of nutrients in water. By increasing [K2O/(CaO+MgO)] ratio, the dissolution rates of the glasses increased due to the shrinking in the rate of crosslinking between phosphate chains, accompanied with a diminution in transition and crystallization temperatures, and an increase in the molar volume. An agronomic valorization of VF1 and VF2 glass fertilizers, which showed dissolution profiles adequate to the criteria of controlled-release fertilizers, was carried out to evaluate their efficiency on tomato crops. These glass fertilizers improved soil mineral content and tomato performances in comparison to the control and NPK treatments with the distinction of VF2. The results highlight the effectiveness of these smart fertilizers toward their potential large-scale application to improve crop production and quality for high nutritional value foods.

Elaboration and Characterization of Vitreous Fertilizers and Study of Their Impact on the Growth, Photosynthesis, and Yield of Wheat (Triticum durum L.)

Four different phosphate glass formulations (F0, F1, F2, and F3) were developed according o wheat nutrient requirements to be used as controlled-release fertilizers. These glasses contain macro-elements (P2O5-K2O-CaO-MgO), with the addition of microelements (Fe-Mn-Zn-B-Cu-Mo) in each formulation. The effects of these elements’ addition on thermal properties, glass structure, and dissolution behaviors were investigated. Results showed that these glasses are composed essentially of metaphosphate chains and that the addition of micronutrients could change the chemical durability of phosphate glasses. A greenhouse experiment was performed using wheat (Triticum durum L.) to evaluate the efficiency of the four glasses, with or without application of chemical nitrogen (N) (N + VF and VF, respectively). The different formulas were tested using two rates of 0.3 and 1 g per plant. In addition to the vitreous fertilizer formulations, two other treatments were applied: control treatment with no amendment and Nitrogen-Phosphorus-Potassium treatment with the application of the conventional fertilizers on the base of optimal rates. After four months of cultivation, vitreous fertilizers application significantly improved growth (7% to 88%), photosynthetic (8% to 49%) parameters, and yield (29% to 33%) compared to NPK treatment and to the control. It has been found that formulas F1, F2, and F3 may constitute a potential alternative to conventional fertilization due to their positive impact on wheat production and can be used in practice as an environmentally controlled-release fertilizer.