Long-term use of different N, P, and K rates and ratios and its effect on chemical composition of hard wheat

Abstract

After 40 years of using different rates and ratios of nitrogen, phosphorus and potassium in a long-term stationary trial, we studied the effects of these treatments on the levels of biogenic macro- and micro-elements in the flag leaf and grain of hard wheat. Our study showed that the treatments had more effect on the levels of said elements in the flag leaf than the grain. Of the three nutrients, nitrogen had the largest influence. The levels of the elements studied were the lowest in the control treatment and the one where only potassium fertilizer had been used. Increasing fertilizer rates of all three nutrients increased to varying degrees the levels of all macro- and micro-elements under study. Nitrogen affected grain yield the most. With the exception of nitrogen, the use of different rates and ratios of N, P and K did not have any major effect on the levels of the elements studied in the grain. The nitrogen content was the smallest in the control treatment nitrogen-free treatments and treatments with the smallest nitrogen rate. In spite of the long-term incorporation of N, P and K, which exceeded the amounts of these elements removed by yield, there was no interaction between the three nutrients and the elements studied. According to the results of our study, even after long-term fertilization with increased N, P and K rates when chernozem has a good supply of phosphorus and potassium and a medium supply of nitrogen, nitrogen will be the element with the largest influence on the grain yield of hard wheat as well as on its chemical composition, as N levels increase in both the flag leaf and grains of this crop.

U stacionarnom, dugotrajnom poljskom ogledu posle četiri decenije primene različitih doza i odnosa azota, fosfora i kalijuma, ispitan je njihov uticaj na sadržaj biogenih makro i mikroelemenata, u listu zastavičaru i zrnu. Primena različitih doza i odnosa azota, fosfora i kalijuma u većoj meri je uticala na sadržaj ispitivanih elemenata u listu zastavičaru nego u zrnu. Od ispitivana tri hraniva azot je ispoljio najveći uticaj. Najmanji je bio sadržaj ispitivanih elemenata kod kontrole i varijante kod koje je primenjivano samo kalijumovo đubrivo. Sa povećanjem doza primenjenih hraniva povećao se sadržaj u manjoj ili većoj meri svih ispitivanih elemenata. Azot je u najvećoj meri uticao i na prinos zrna. Primena različitih doza i odnosa azota, fosfora i kalijuma nije ispoljila veći uticaj na sadržaj ispitivanih elemenata u zrnu, osim u slučaju azota. Sadržaj azota bio je najmanji kod kontrole, varijanata kod kojih nisu primenjivana azotna đubriva i pri upotrebi najmanje doze azota. I pored višegodišnje primene doza azota fosfora i kalijuma koje premašuju njihovo iznošenje prinosima nije došlo do interakcije između primenjenih i ispitivanih elemenata. Na osnovu dobijenih rezultata može se zaključiti da na černozemu dobro obezbeđenog u fosforu i kalijumu i osrednje u azotu, i posle višegodišnje primene povećanih doza azota, fosfora i kalijuma najveći uticaj ne samo na prinos zrna već i na hemijski sastav ima azot, povećavajući pre svega njegov sadržaj kako u listu zastavičaru tako i u zrnu.