Плешкуца, Любов; Plescuta, Lyubov
Ефект на системите на торене върху продуктивността на двуполно сеитбообръщение твърда пшеница – памук
Effect of the fertilization system on the productivity of two-crop rotation durum wheat-cotton
пшеница; памук; двуполно сеитбообръщение; торене
Effect of fertilization with increasing levels N ( 0; 80; 120; 160 kg.ha-1 and P (0; 80; 120 kg.ha-1) on productivity of durum wheat and cotton in rotation was investigated. The highest durum wheat grain yield was obtained at combined fertilization N120P120 - 3.94 t.ha-1***. Alone N 120 kg.ha-1 fertilization led to obtaining of 3.75 t.ha-1 which exceeds fertilization with N 160 kg.ha (3.55 t.ha-1). Alone phosphorus fertilization is insignificant. The N fertilization rate is the strongest source of variation (66.80% of total effect) and phosphorous nutrition has 1.73% influence. Agronomic efficiency (AE) for N and P decreased with increasing of fertilizing rates. AEN was average 6.53-11.15 kg.kg-1, and AEP - 0.83-1.17 kg.kg-1. The harvest index of durum wheat grain variety Predel was average 0.353. The total yield of seed-cotton without fertilization was on average 1.32 t.ha-1. As a result of N fertilization, the average yield increased with 26.6 (N80) to 32.9% (N120) compared to non-fertilized, and for phosphorous fertilization - to 2.9% for P80. In the case of combined fertilization, the N120P80 recorded the highest average yield – 1.82 t.ha-1, 37.8% above the non-fertilized. An optimal nitrogen norm of those tested in moderate soil stock is N120.