BIOMASS AND CRUDE PROTEIN OF TWO FORAGES FERTIGATED WITH TREATED DOMESTIC SEWAGE

Giovanni De Oliveira Garcia,Michelle Machado Riggo,Roberto Avelino Cecílio,José Guilherme Bergamim Mellere,Edvaldo Fialho Dos Reis

doi:10.13083/reveng.v24i4.529

Abstract

The reuse of wastewater in agricultural activities has been identified as alternative to final disposal of minimal risk to the environment. Accordingly, in order to assess the yield and crude protein content of forages Tifton 85 (Cynodon spp.) and Marandu grass (Brachiaria brizantha) fertigated with treated domestic sewage compared with those grown with mineral fertilizer, two split plot experiments were set: one with each species at 5x3 factorial arrangement and five repetitions. The factors in the plots corresponded to five treatments, one fertilized with mineral fertilizer in which was applied 40 kg ha-1 of nitrogen and four fertigated with treated domestic sewage in the dosages of 20, 40, 60 and 80 kg ha-1 of nitrogen and, three plant sections in the subplots. After each section the plant material had its green mass determined and then sent to the laboratory for measurement of dry mass. Also in the laboratory, the crude protein content was determined. The application of treated wastewater used in the form of fertigation resulted in increased biomass and crude protein reflecting better nutritional value of forages studied.

Highlights

Pastures occupy approximately 25% of the land area, while Brazil has more than 200 million hectares of grassland, being largely composed of natural pastures
The objective of this work was to evaluate the yield and crude protein content of forages Tifton 85 (Cynodon spp.) and Marandu Grass (Brachiaria brizantha) fertigated with treated domestic sewage in four application rates under greenhouse conditions compared with those grown with mineral fertilizer
The yield, dry matter and crude protein content of Tifton 85 and marandu grass were influenced by the interaction among treatments applied and sections (p < 0.05)

Summary

Introduction

Pastures occupy approximately 25% of the land area, while Brazil has more than 200 million hectares of grassland, being largely composed of natural pastures. The use of nitrogen fertilizers aims at increasing the recovery of nitrogen applied to the soil-plant system, once besides the dry mass production, this nutrient promotes improved quality of forage produced and increased capacity of animals per area (BENNETT et al 2008). Brazil has area and environmental conditions favorable to the development of pastures, which in some cases are under degradation conditions, reducing the production of green mass and nutritional values for animal production. Another aspect is the tendency of the soil to the erosive effects, once the low vegetation cover provides areas of compression reducing the soil’s water infiltration capacity (ZIMMER et al 2002). Considering the fate of clean water sources for human consumption, in recent years, the advancement of technical and scientific knowledge regarding the potential for water reuse contributed to the increased interest in the use of wastewater in agricultural crops (VILLELA JÚNIOR et al, 2003)

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Results