Effects of Dolomitic Limestone on some the Physical-chemical Properties and Yield of Sugarcane in a Vertisol

The application of natural mineral and organic fertilizers can increase soil productivity. The work was carried out on Vertisols under the sugarcane crop. The research aimed to assess the effect of dolomitic limestone on some physical-chemical properties and the yield of sugar cane in a Vertisol. An experiment was conducted with dolomitic limestone levels and combinations of organic fertilizers (compost, sugarcane filter cake) and fertilizers (NPK). The design used was stripe blocks. The soil analysis data used at depths of 0-20 and 20-40 cm were at 8, 19 and 36 months after the treatments were applied. The following indicators were evaluated: structure factor, permeability, water-stable aggregates, plasticity, T value, and exchangeable cations. Dolomitic limestone and its combinations with organic fertilizers showed significant positive effects on soil structure and consistency, both in the surface layer and in the subsoil, with residual impact over time up to 36 months. The results obtained showed a change in the category of structural indicators from regular to excellent (permeability 1.50-2.40) and from plasticity to moderately plastic (Plasticity index 36.64 -13.72). The results demonstrated that the structure and stability indicators under study conditions reached positive and significant correlations (R2 0.70) with the sugarcane yield in t ha-1 even 36 months after planting the crop, which confirms the residual effect of the treatments.