Effect of sugar industry wastes on K status and nutrient availability of a newly reclaimed loamy sandy soil

Abstract

A greenhouse study was conducted to evaluate the effect of sugar cane industry wastes on K status and its availability in a newly reclaimed loamy sand soil, as well as their influence on some chemical soil properties and soil macro- (N and P) and micronutrients (Fe, Zn, Mn, and Cu) availability to wheat plants. The applied treatments were mineral K fertilizer (K₂SO₄), vinasse, bagasse ash and organo-mineral fertilizer (Tacamolia), as well as the control. The treatments were added on the K-equivalent basis (25, 50 and 100 mg K kg⁻¹). The results indicated that sugar cane wastes incorporated into the loamy sand soil affected the forms of soil K, Q/I ratio parameters, and K availability to wheat plants. Water-soluble K, NH₄OAc-extractable K, and HNO₃-extractable K significantly increased with increased application level of K₂SO₄ or sugar cane wastes. Greater increases in K forms, Q/I relationship parameters (equilibrium activity ratio for K, labile K and potential buffering capacity) and K availability to wheat plants were pronounced for the organo-mineral fertilizer (Tacamolia) than for other treatments. Both Tacamolia and vinasse added caused a significant decrease in soil pH and significant increases in soil available P, total N, and total organic C. Moreover, additions of sugar wastes, especially Tacamolia, markedly increased the nutrients utilization by wheat plants. Therefore, recycling of sugar industry by-products can be used as organic fertilizer, which may substitute for the other chemical and organic fertilizers for soil improvement.

Keywords:

• sugar cane industry wastes
• K forms
• Q/I ratio parameters
• nutrient availability