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

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.