Manejo de solo para viabilizar o cultivo de milho em áreas de várzea

Abstract

The state of Rio Grande do Sul has an idle lowland area of about 2 million hectares, these areas that are fallow waiting to receive the culture of the Irrigated Rice. Years of successive crops in the same areas provided a weed infestation, which has resulted in a reduced productivity. How often operations are carried out with an excess of moisture condition, due to the intrinsic hydromorphism these areas where friable condition has a small range, these generally operations cause the appearance of compacted layer in the subsurface, which is practically common all state lowland areas where rice culture is installed. Crop rotation is good tool to reduce weed infestation and still generate income in an area that normally would be under naturalized vegetation. However, the hydromorphism these areas almost impossible the cultivation of rainfed crops. The small number of macropores difficult aeration and infiltration, and as generally the flood plains are flat, the soil will be saturated by a larger time. The use of soil management techniques to help provide a better environment for the development of plants is crucial to the success of rotation of rainfed crops with rice. The objective of this study was to evaluate the effects of four soil tillage and sowing the physical attributes and the development of maize (Zea mays L) in lowland soil. For this experiment was carried out in the region of the Western Frontier in the municipality of Alegrete. The experiment was conducted in a randomized block design with four replications and four treatments namely conventional T1, T2 ridge, T3 and T4 scarified + ridge - scarified in which analyzes were performed in 4 soil layers that are: 0-5cm, 5-10cm, 10-20cm and 20-30cm. The following soil physical properties were analyzed: density, porosity and infiltration rate. Data were subjected to statistical analysis F test at 5% probability of error. The results of the analysis of physical attributes observed in better aeration T2 in the top two layers , but did not differ T3 and T4 . For VIB there was no significant difference between treatments , because of the high coefficients of variation , but in absolute values T3 had a higher VIB than the others. For estabelecias population of plants T2, T3 and T4 were significantly different from T1 , T2 and the treatment with the highest absolute value of established plants. Productivity followed the trend of plant population being more productive T2 , however , not different from T3 and T4. With results we can get a better understanding of the dynamic processes of the floodplain environment and check the possibility of using corn as an alternative to crop rotation in this environment.