Cover crops affect the soil chemical properties under no-till system

The purpose of this study was to assess the changes in soil chemical properties affected by the cover crops cultivated in crop rotation in short-term of no-till implementation under Rhodic Hapludox soil. This research was carried out from October 2010 to February 2014. The experiment was set up in completely randomized blocks in a factorial design with eight treatments (cover crops) and three soil depths (0-5, 5-10 and 10-20 cm) with four repetitions. The cover crops were: fall-winter maize (T1), intercropping fall-winter maize with B. ruziziensis (T2), intercropping fall-winter maize with B. brizantha cv. Marandu (T3), intercropping fall-winter maize with Crotalaria spectabilis (T4), B. ruziziensis (T5), B. brizantha cv. Marandu (T6), Pennisetum glaucum L. (T7) and fallow (T8). The T6 and T7 affected exchangeable Mg +2 , it was observed higher exchangeable Mg +2 in T6 (2.39 cmolc dm -3 ) and T7 (2.43 cmolc dm -3 ) in comparison to T1. The phosphorus content showed interactive effect between cover crops and soil depth. In the comparison among the depths, the P contents were higher in 5-10 cm, which showed improvement of 24.6% and 25.2% in comparison to 0-5 and 10-20 cm layers, respectively. The cover crops evaluated in this research affected the exchangeable Mg +2 and K + , as well as Mg +2 and K + saturation. The P content changed in response of cover crops, which was important to observe that this nutrient may increase the content with adoption of cover crops in no-till system. The species used in this research might be recommended to integrate a crop rotation system with the possibility of increasing P availability in topsoil depth in no-till system.