Relationship between the phosphorus balance of Hungarian long-term field trials, trend of yields, and soluble phosphorus content of the soils
Titel:
Relationship between the phosphorus balance of Hungarian long-term field trials, trend of yields, and soluble phosphorus content of the soils
Auteur:
Debreczeni, K. Sisak, I.
Verschenen in:
Communications in soil science and plant analysis
Paginering:
Jaargang 27 (1996) nr. 5-8 pagina's 1647-1661
Jaar:
1996-03
Inhoud:
The long-term changes in the first 20 years of the Hungarian National Long-Term Fertilization Trials were studied. Eleven treatments were selected for the study: unfertilized control, a large dose of fertilizers [250-66-80 kg/ha of nitrogen (N), phosphrous (P), and potassium (K), respectively], and all combinations of 50-100-150 kg/ha N and 0-22-44 kg/ha P with 80 kg K/ha. Three experiments, started in 1967, 1968, and 1969, consecutively, were included in the analysis with same crop rotations of wheat-maize-maize-wheat. Positive linear trends in yields were seen over the course of the experiment, even on the unfertilized plots. Nitrogen and P fertilization had strong influences on the slopes of trends. Ammonium lactate-soluble P content in the soil plough layer also increased if P fertilizer was applied. Linear trends of nutrient content on yield were also seen in some treatments: positive for N and both negative and positive for the P. Nitrogen uptake increased in every treatment even in the unfertilized one. Phosphorus uptake increased at the higher P supply (44 kg P/ha). Phosphorus input was approximately equal to output at the 22 kg P/ha level, although the soluble soil P content increased at aproximately 10% of the fertilizer input.