Sewage sludge as nitrogen and phosphorus source for cane-plant and first ratoon crops

Abstract

SUMMARYThe use of sewage sludge in Brazilian agriculture was regulated by the resolution no. 375 Conama, in 2006. However, there is a lack of research to adequate the mineral N and P fertilizer doses to be applied in agricultural fields treated with this residue. In a field experiment, the effects of application rates of sewage sludge and mineral N and P fertilizers on the productivity and technical characteristics of the cane-plant and first ratoon (residual effect) crops were evaluated. Four doses of sewage sludge (0, 3.6, 7.2 and 10.8 t ha -1 , dry base), of N (0, 30, 60 and 90 kg ha -1 ) and of P 2 O 5 (0, 60, 120 and 180 kg ha -1 ) were combined in a factorial and laid out on randomized block design, a with two replications. To evaluate the residual effect of the sludge, 120 kg ha -1 N and 140 kg ha -1 of K 2 O were applied in all plots. Sludge application at cane planting, with or without N and/or P fertilizer increased the stalk yield from 84 up to 118 t ha -1 , with no alteration in the sugarcane quality, compared with the application of NPK fertilizer alone, resulting in a stalk yield of 91 t ha -1 . The study of the response surface for stalk yield on lowfertility soil was the basis for a recommendation of mineral N and P fertilizer doses for sugarcane implantation as related to sewage sludge application rates. It was also concluded that a sludge application of 10.8 t ha -1 , which is the sludge dose established based on the N criterion according to the resolution Conama n o 375, could a) reduce the use of mineral N by 100 % and of P 2 O 5 by 30 %, with increments of 22 % in stalk yield, as a direct effect of sludge application to cane plant crop, and b) increase the stalk yield in the second harvest (first ratoon) by up (1)

Characterization of sewage sludge generated in Rio de Janeiro, Brazil, and perspectives for agricultural recycling

“…Some studies have demonstrated the advantages of fertilizing these crops with sewage sludge, such as improved soil quality, productivity gains, less dependence on chemical fertilizers, lower production costs, among others (CHIBA et al, 2009;FRANCO et al, 2010;JUNIO et al, 2013;MAIA, 2013;MARTINS et al, 2005;YADA et al, 2015). Sewage sludge recycling in these agricultural areas can represent considerable savings with chemical fertilizers, providing economic, environmental, and social benefits.…”

“…Sewage sludge recycling in these agricultural areas can represent considerable savings with chemical fertilizers, providing economic, environmental, and social benefits. Chiba et al (2008) and Franco et al (2010) analyzed the efficiency of sewage sludge in sugarcane fertilization and concluded that sludge can supply up to 100% of nitrogen fertilizer requirement. Since sugarcane is the main agricultural crop in Rio de Janeiro State, the use of sewage sludge as fertilizer should be treated as a strategic issue for the agricultural sector of Rio de Janeiro.…”

Agronomic Efficiency of Biosolid as Source of Nitrogen to Banana Plants

“…The nitrogen mineralization rate (N MR ) was determined in a laboratorial trial (data not shown) and was equal to 30% of total N. For planting (2) and growing seasons 2 and 3 (3) amendments two different equations to estimate SS N were used:…”

“…The key concept of land application of biosolid [1][2][3] is the return of organic matter and plant nutrients removed by crops. Some researchers have reported that biosolid application also improves soil physical properties [4][5][6].…”

“…Some researchers have reported that biosolid application also improves soil physical properties [4][5][6]. Biosolids were effective to substituted mineral fertilizers as source of nitrogen (N) for ryegrass [7], sugarcane [1,2,8], sunflower [9], and maize [10,11]. In all of these, there were no indications of environmental hazards due to biosolid addition in soils.…”