Changes in the N/S ratio and in the total S and N contents of the grain were investigated in one maize hybrid and one wheat variety grown in calcareous loamy chernozem soil at the Experimental Station of Debrecen Agricultural University. The crops were sown in mono-, di- (wheat, maize) and tricultures (pea, wheat, maize) within the framework of an NPK fertilisation experiment and the above parameters were studied as a function of time. The experiment consisted of combinations of 5 fertilisation treatments, 3 irrigation treatments and 3 soil cultivation treatments in 4 replications, giving a total of 180 treatment combinations. The soil was slightly acidic (pHaq=6.4) with a moderately high humus content (2.5-3.0%), poor phosphorus and zinc supplies and good potassium, manganese and copper supplies. The CaCC3 content in the top 0-20 cm layer was 0%. The weather was similar in all the growing seasons investigated, with the exception of 1992, when the weather was dry even at the beginning of the growing season, followed by even less rainfall and high temperatures later. The total S concentration in wheat grains increased by 18% between 1988 and 1992, while this figure was 33% for maize. The sulphur content in the control also increased, by only 6% in wheat grains but by 35% in maize. In wheat this sulphur increase was advantageous, as it approached the generally accepted critical lower limit (0.12%). The total N content increased by 14% in both wheat and maize grains. There was hardly any increase in the N content of control wheat grains (0.6%), while in control maize grains this figure was high (14%). Thus, both the sulphur and nitrogen contents rose in the period 1988-1992 (possible reasons for this are atmospheric deposition and fertiliser treatment), but the rate of increase was not the same for the two elements, so the N/S ratio in wheat grains decreased from 15.03 to 14.54 (from 14.91 to 14.30 in the control) and that of maize grains from 16.10 to 13.67 (from 15.59 to 13.34 in the control). This decrease in the N/S ratio was favourable. No sulphur deficiency was observed. There was an unambiguous linear relationship between the N and S contents.
|Number of pages||10|
|Publication status||Published - Apr 1 1996|
ASJC Scopus subject areas
- Agronomy and Crop Science