Laboratory study of the nutrient release rate for vinasse on sandy soil and three coastal clay soils of Guyana

Abstract

<strong>Purpose</strong> Vinasse is produced in large quantities as a by-product from bioethanol production. To ensure environmental sustainability, a beneficial use was sought. Previous study showed that short-term crops grown with vinasse-amended soil provided higher yield than crops treated with chemical NPK (15:15:15) fertilizer. To understand this phenomenon, this study sought to establish the nutrient release rates of vinasse in the agricultural soils of Guyana.<br /> <strong>Methods</strong> Soils representative of the three most common and one futuristic agricultural land in Guyana were fertilized with vinasse, then watered as with normal course of plant growth of cash-crops for twelve weeks. The soil was sampled periodically, and the soil nutrients were determined.<br /> <strong>Results</strong> The nutrient availability from the application of vinasse as a soil amendment was greater for the clay soils than the sandy soil. EC was high while there was high availability of N, Ca, Mg, Fe and Mn during the 6-12^th week. There was no discernable trend for tiwiwid sand.<br /> <strong>Conclusion</strong> In this laboratory study, high nutrient availability was observed in weeks 6-12 for the three clay soils studied. This period is the fruit and foliage growth phase for most short-term crops; hence, this suggests that vinasse is a good soil amendment for short-term crops in these soils. Vinasse did not improve the fertility of sandy soils; hence, it would be unsuitable as a fertilizer source in the Intermediate Savannahs of Guyana. Further studies should be done to fully determine the soil nutrient dynamics and the nutrient uptake.