Wheat biometric parameters in third application of composted sewage sludge and wastewater drip irrigation

Abstract

Sewage sludge and wastewater contain high levels of organic matter and nutrients, therefore, they can be a promising alternative for use in agriculture, mainly in the replacement or supplementation of traditional agricultural fertilizers, which often are expensive. The objective of this study was to evaluate the wheat response (Triticum aestivum) through the application of composted sewage sludge as fertilizer nitrogen under irrigation with drinking water (DW) and wastewater (WW). The design was completely randomized, in the scheme of subdivided plots, with 10 replications. Seven levels of nitrogen fertilization (subplot) distributed in two experimental plots, represented by irrigation with DW and WW, were defined: T1 = no nitrogen fertilizer in the soil; T2 = 100% chemical nitrogen fertilization; T3 = 50% of chemical nitrogen fertilizer + 50% nitrogen fertilization via composted sewage sludge (CSS); T4, T5, T6 and T7 corresponded to 100, 150, 200 and 250% of nitrogen fertilization via LEC respectively. The results indicate the possibility of replacing the chemical nitrogen fertilization, 80 kg ha^-1 of N, by the equivalent in CSS, without any damage to the crop. In soil not fertilized with N, irrigation with treated sewage was beneficial to wheat, providing a 60% increase in the number of grains per plant.