S. KOSTADINOVA1 and G. PANAYOTOVA2
1 Agricultural University, BG-4000 Plovdiv, Bulgaria
2 Cotton and Durum Wheat Research Institute, BG-6200 Chirpan, Bulgaria
KOSTADINOVA, S. and G. PANAYOTOVA, 2003. Agronomic and energetical efficiency of fertilization in cotton. Bulg. J. Agric. Sci., 9: 161–166
The investigation was carried out on the testing field of the Cotton and Durum Wheat Institute, Chirpan in a long-term trial at cotton-durum wheat crop rotation under non-irigated conditions. The rates of fertilization for N and P2O5 were 0, 8, 16 and 24 kg.da–1, and for K2O – 0 and 16 kg.da–1.
The objective of the present investigation is to examine the agronomic and energetical efficiency of mineral fertilization of cotton under conditions of long term fertilizing experiment for period of five years.
It was found that the weather conditions was determined the seed-cotton yield. In a year with favorable weather conditions the mean yield was 270 kg.da–1, while in a year with less favorable weather the yield was 92 kg.da–1. The agronomic efficiency was slightly depended on the fertilizing system. The year conditions were showed the main effect on it. The energetical efficiency of the fertilization (h) varied significantly among the years than according to the fertilization. The lowest values of h were found in a years with less favorable weather conditions (0.16 and 0.15 units) and the highest energetical efficiency (means of fertilization systems) was recorded in 1999 (0.59 units).