Preparation, Characterization of Granulated Sulfur Fertilizers and Their Effects on a Sandy Soils

There is a potential for using sulfur waste in agriculture. The main objective of this study was to design a granular fertilizer based on waste elemental sulfur. Humic acids and halloysite were used to improve the properties and their influence on soil properties. This is the first report on the use of proposed materials for fertilizer production. The following granular fertilizers were prepared (the percentage share of component weight is given in brackets): fertilizer A (waste sulfur (95%) + halloysite (5%)), fertilizer B (waste sulfur (81%) + halloysite (5%) + humic acids (14%)), fertilizer C (waste sulfur (50%) + halloysite (50%)) and fertilizer D (waste sulfur (46%) + halloysite (46%) + humic acids (8%)). Basic properties of the obtained granulates were determined. Furthermore, the effect of the addition of the prepared fertilizers on soil pH, electrolytic conductivity, and sulfate content was examined in a 90-day incubation experiment. Enrichment with humic acids and the higher amount of halloysite increased the fertilizer properties (especially the share of larger granules and bulk density). In addition, it stabilized soil pH and increased the sulfur content (extracted with 0.01 mol·L−1 CaCl2 and Mehlich 3) in the soil.

Influence of limestone ameliorants and fertilizers on the winter wheat productivity in crop rotation

The influence of mineral fertilizer (N120P60K90) with sulfur addition, and foliar dressing by micronutrients, various doses, and types of limestone ameliorants on the formation of the morphological structure and the productivity of winter wheat was shown. The aim of the research was to establish the regularities of various forms and doses of chemical ameliorants in combination with mineral fertilizers influence on the yield of winter wheat on soddy-podzolic soil in the conditions of the West Polyssia. The application of ameliorants on the background of fertilization increased the indicators of the yield structure and plants survival. The highest results were obtained by using 1,5 and 1,0 doses dolomite flour (determined by the hydrolytic acidity) in complex with S40 and foliar dressing with microfertilizer. The obtained results were ear length – 9,0 and 9,2 cm, number of grains in an ear – 41,1 and 41,4 pcs. The mass of 1000 grains were respectively 43,8 and 43,7 g. The death of plants during the vegetation season from germination to harvesting was low – 18,2 and 19,0 %. It was founded that among the studied various doses and forms of limestone ameliorants on the background of N120P60K90, the application of 1,5 doses of dolomite flour contributed to increase pHKCl by 1,93 units (initial data pHKCl 4,47) and to grow up the winter wheat productivity on soddy-podzolic soil. The highest yield a 3,9 and 4,0 t/ha were ensured by the application of 1,5 doses and 1,0 doses dolomite flour in combination with S40 and microfertilizer on the background of N120P60K90. The yield increase to the control (without fertilizers) was 2,61 and 2,71 t/ha, to the background (N120P60K90) – 1,58 and 1,68 t/ha. The addition of sulfur fertilizers (S40) and two-time foliar feeding with Nutrivant Plus Cereals (2 kg/ha) during the spring tillering phase and stem elongation provided an 8% increase in yield.

Subsoil-potassium depletion accounts for the nutrient budget in high-potassium agricultural soils

Continuous potassium (K) removal without replenishment is progressively mining Argentinean soils. Our goals were to evaluate the sensitivity of soil-K to K budgets, quantify soil-K changes over time along the soil profile, and identify soil variables that regulate soil-K depletion. Four on-farm trials under two crop rotations including maize, wheat and soybean were evaluated. Three treatments were compared: (1) control (no fertilizer applied); (2) application of nitrogen, phosphorus, and sulfur fertilizers -NPS-; and (3) pristine condition. After nine years, crops removed from 258 to 556 kg K ha−1. Only two sites showed a decline in the exchangeable-K levels at 0–20 cm but unrelated to K budget. Topsoil exchangeable-K levels under agriculture resulted 48% lower than their pristine conditions, although still above response levels. Both soil exchangeable-K and slowly-exchangeable K vertical distribution patterns (0–100 cm) displayed substantial depletion relative to pristine conditions, mainly concentrated at subsoil (20–100 cm), with 55–83% for exchangeable-K, and 74–95% for slowly-exchangeable-K. Higher pristine levels of exchangeable-K and slowly-exchangeable-K and lower clay and silt contents resulted in higher soil-K depletion. Soil K management guidelines should consider both topsoil and subsoil nutrient status and variables related to soil K buffer capacity.

The usefulness of sulfur fertilizers for balanced nutrition of spring wheat on zonal soils of the south-western Forest steppe zone

The importance of sulfur for a balanced nutrition of grain crops is demonstrated. The content of mobile forms of sulfur in the main zonal soils of the Kursk region – black soil and gray forest soils is given. Gray wooded soils have a low content of mobile sulfur in most areas of the region. The availability of sulfur in black soil ranges from low to medium. Practical studies on the effectiveness of different types and forms of using sulfur-containing mineral fertilizers in the cultivation of spring wheat on zonal types of soils in the south-western forest steppe of the Central Black Earth Region have been performed. Research has found that the practicability of using sulfur-containing mineral fertilizers and their agronomic effectiveness is directly associated with the content of available forms of sulfur in the arable layer of the soil. It is most effective and reasonable to use sulfur-containing mineral fertilizers in the cultivation of spring wheat on gray wooded soils. The practical data obtained prove the urgency of the use of sulfur-containing fertilizers in technologies for the cultivation of grain crops on soils with inadequate content of available forms of sulfur.