Biomassa, atividade microbiana e produtividade de trigo e milho em solo com histórico de aplicação de fontes orgânicas e mineral

Abstract

The use of organic waste arising from the production of pigs and cattle is commonly used to fertilize crops. Successive applications of these sources in the same areas over time promote changes in physical, chemical and biological soil, they can play some influence on biomass and activity of soil microbes, which may reflect the availability of nutrients and consequently in crop productivity. This study aimed to evaluate how the activity and microbial biomass can be changed in soil under no-tillage system and with a history of successive applications of organic and mineral sources.The experiment was established in 2004 and has been conducted in the experimental area of the Department of UFSM soils under a Ultisol and design of randomized blocks. The results of this study correspond to the period of the agricultural year 2014/2015 which was grown wheat succession (winter) and maize (summer) .The treatments consist of application of pig slurry (PS), liquid cattle manure (CS) , pig deep-litter (PL), mineral fertilizers (NPK) and a treatment without nutrient source application (TEST), the quantity applied these sources based fertilizer recommendation to the state of RS and determined by the dose N required by the crop When he turned up 11 years of applying treatments, soil samples were collected at 0-10 cm during the wheat crops and corn, in both the flowering period and after harvesting crops . Part of the samples followed for chemical characterization and part was stored at 4 °C for determination of C, N and P of the microbial biomass, respiration rate and activity of B-glucosidase enzyme, urease, aryl sulphatase, acid phosphatase, and hydrolysis of FDA. The results showed differences from organic sources with each other and with respect to TEST and NPK. In wheat cultivation there was no difference between treatments for C-BIO variable. The N-BIO did not differentiate between organic sources, but these were higher compared to TEST and NPK treatments. PL and CS treatments also had higher values for P-BIO. Already maize cultivation PL and CS stood out in relation to other treatments for C, N and P-BIO. These same treatments was observed the highest respiration rates in both the wheat crop as corn, but also had higher qCO2 values. In general for all the enzymes evaluated in this study the PL and CS were the treatments with the highest activities.