Effect of compost made with sludge from wastewater treatment plants on field of corn (Zea mays L.) and arbuscular mycorrhizal fungi density

Abstract

In this study we evaluated four composts prepared with different proportion of sludge from two wastewater 
treatment plants, a soft drink and a paper industry, mixture with and without chili residues. They were tested over 
yield of corn and population of arbuscular mycorrhizal (AM) fungi. Sludge was composted producing a non 
phytotoxic material with good physical and chemical properties. Corn cultivated with the application of the four 
composts grow higher than control (without compost) and in fertilized plot. Considering the corn production it was 
higher too in plots applied with composts 2, 3 and 4 than in control, and it was similar with those obtained in 
fertilized plot. There were significant differences in the number of Arbuscular mycorrhizal fungi spores found in 
samples of soil with application of compost, comparing with control and fertilized plots; application of composts 
improve the growth and yield. Making compost with sludge from wastewater treatment plants is an excellent way to 
valorize the residues, because it organic matter and minerals could be transformed into compounds that even 
could recover the soil fertility.