| Popis: |
Efficient fertilizer management in maize production is based on supplying adequate amounts of nutrients for optimum economic yield, while minimizing losses to the environment. Exploiting genotypic differences in fertilizers use is required for achieving nutrient-use efficiency and higher yield. This two-year field study was designed to evaluate the influence of different fertilizer combinations on nitrogen (N), phosphorus (P) and potassium (K) uptake patterns, and yield in novel maize hybrids. Four divergent maize hybrids NS 4023, NS 6010, NS 6030 and NS 640 were grown under eight NPK combinations: 1: P60K60; 2: P60K60 N-min (spring); 3: P60K60 + N40autumn Nmin (spring); 4: P60K60 +/- N-60spring; 5: P60K60 N-100spring; 6: P60K60 N-40autumn N-60spring Zn; 7: P60K60 +/- N-40autumn N-80spring Zn; 8: P60K60 + N-160spring + Zn in both years of study. Different NPK combinations significantly improved NPK contents in leaves and grains along with substantial increase in 1000-grain weight, grain yield, grain protein contents and net returns of all tested hybrids; however, hybrids behaved differently in this regard. The highest N content in maize leaves was found in NS 4023 (2.39%), potassium in NS 6030 and NS 6010 (1.73%). Fertilizer combinations with N addition in autumn and spring + Zn, fertilization based on N correction in spring, showed positive effects on N content in grain and leaves; however P contents in leaves were not affected with fertilization systems. Moreover, P and K concentrations in leaves and grains decreased, which may be associated to better efficiency of maize hybrids. The highest yield was obtained with P60K60 + N-40 autumn + N-60 spring Zn followed by fertilizer combinations, P601(60 N40 autumn + N-80 spring Zn and P60K60 + N-40 autumn + N-min spring. The highest net benefit of 2091.6 and 2043.9 $ ha(-1) was obtained in treatments: P60K60 +N-40 (autumn) + N-60 Zn-spring and P60K60 N - (40 autumn) + N-min (spring). In conclusion, the amount and timings of nutrients application significantly affect the yield and could help in determination of genotype potential. Moreover, the treatment combination, P60K60 + N-40 (autumn )+ N-60 (spring) Zn harvested maximum maize yield along with highest net benefits and benefit: cost ratio. |
