INFLUÊNCIA DO USO DE COBERTURA SOBRE A RESISTÊNCIA DO SOLO À PENETRAÇÃO E EFICIÊNCIA DO USO DA ÁGUA NAS CONDIÇÕES EDAFOCLIMÁTICAS DO TRÓPICO ÚMIDO

Abstract

In the humid tropics, construction and soil fertility maintenance represent a challenge for farmers and also for the researchers who are dedicated to the implementation of sustainable farming systems. The objective was to evaluate the influence of ground cover use of inorganic nitrogen and increase efficiency of water use on the soil mechanical resistance to penetration, chlorophyll content and productive corn parameters in the agri-environmental conditions of the humid tropics. The treatments were: soil cover with corn + inorganic nitrogen (Ninorg) + shift watering every 4 days (4CN); Corn with ground cover + shift watering every 4 days (4C); Without mulching corn + shift + Ninorg watering every 4 days (4SN); Corn without soil cover + shift watering every 4 days (4); Corn with ground cover + shift + Ninorg watering every 8 days (8CN); Corn with ground cover + shift watering every 8 days (8C); Without mulching corn + Ninorg + shift watering every 8 days (8SN); Corn without cover soil + shift watering every 8 days (8S). In reading I to relative chlorophyll content (CRT I) 4CN treatment differed from all the other treatments being similar only with the 4SN treatment. Soil moisture levels differ between treatments in the evaluations performed at 4 and 8 days after irrigation, the evaluation performed at 4 days after irrigation, the 4CN treatments, 4C and 8C with higher percentages differ from 4SN treatments, 4S and 8SN . Regarding the soil penetration resistance (RP), in assessing four days after irrigation was found that there were no differences between treatments in the superficial layers of 0-5 cm, as in the layer 6-10 cm, the 8S treatment differed from other treatments, with higher PR of 1.53 MPa. With respect to the evaluation performed on the 8th day after the irrigation, it was found differences between treatments within each depth and maximum penetration resistance (PMAX). Most productivity components 4CN demonstrates that treatment promoted significant differences when compared to treatments with irrigation every 8 days. Regarding the efficiency of water use, treatment with 8-day irrigation schedule, proved to be more efficient, with the maximum value of 17.28 kg / m3. In view of the foregoing, it is concluded that the efficiency of water usage was higher than in treatments with high turn independently of the presence or non-watering of the soil cover.