Affiliation:
1. Brazilian Agricultural Research Corporation (Embrapa), Embrapa Clima Temperado
2. Federal University of Pelotas - Campus Universitário
3. Geological Survey of Brazil
4. University of Guelph
5. Brazilian Agricultural Research Corporation (Embrapa), Embrapa Cerrados
Abstract
Abstract
This study evaluated regional sources of nutrients to improve the soil fertility status and yield of maize-wheat succession in Southern Brazil. The treatments were: T1: no fertilization; T2: liming with dolomitic marble; T3: alternative liming (AL) with limestone interbedded with shale; T4: AL + 50% P - with Arad natural phosphate (P-ANP) + 50% P – triple superphosphate (P-TSP); T5: AL + 100% P-ANP; T6: AL + 100% P-ANP + 100% K-rich monzogranite; T7: AL + 100% P-ANP + 100% N from tung pressed cake (N-TPC); T8: AL + 100% P-ANP + 100% K-rich monzogranite + 100% N-TPC + 100% S; T9: AL + 100% NPK recommendation (urea, TSP and KCl). Immediate and residual effects were evaluated over 2.5 years (90, 360 and 900 d) on soil fertility and maize - wheat yield. The limestone interbedded with shale released Ca, Mg and corrected soil acidity similarly to dolomitic marble. The monzogranite increased the available K in soil, although improvements of the final product could enhance K release. The fertilization strategies used in T4, T7 and T8 presented a relative productivity index of 108, 111 and 108% when compared to T9 for maize plus wheat yield, while T3 (U$=1223) and T4 (U$=1284) resulted in higher profits (+4.2 and +9.4%, respectively) than T9 (U$=1174). The limestone interbedded with shale combined with 50% of P-ANP + 50% of P – TSP (T4) provided the best economical and technical results, highlighting the potential of selected rock powders for soil fertility correction and plant-nutrients supply.
Publisher
Research Square Platform LLC