Manipueira na fertirrigação: efeito sobre a germinação e produção de algodão (Gossypium hirsutum var hirsutum, L, e milho (Zoa mays. L.)

Abstract

The objective of the present paper was to verify the influence of increasing rates of cassava press water (50; 100 and 200 on cotton and corn, in different times of application, in order to evaluate the fertirrigation techinics in annual crops as a way of avoiding the pollution caused by this industrial efluent in rivers and lakes. The trial was set in field conditions, in randomized blocks, with three replications. As a drastic inhibition was observed the emergence of the seedlings causing stand reductions of 25%; 90% and 100% for cotton and 5%; 64% and 96% for corn, respectively for the rates of 50; 100 and 200 m3 /ha. The dosage of 50 m3 /ha showed high viability, mainly when applied 40 days before planting, although it is necessary to increase the seed density in 20% in the stand, in any time of application. The application of the cassava press water increased the content of phosphorus and potassuim in the soil, mainly, in the rate of 200 m3/ha. Because of the increase on the availability of magnesium and potassuim, it could cause a desequilibruim between the relation of the cationic bases of the soil.