Distribution and forms of phosphorus in carbonate chernozem depending on maize growing systems

Abstract

modern agriculture, global studies are directed toward more efficient use of phosphorus fertilizers, its recycling, and the use of alternative sources. This study is based on monitoring the effect of crop rotation and fertilizers (manure, harvest residues and mineral fertilizers) on the presence of phosphorus and its fractions in different layers of rhizosphere by long-term use of particular maize growing systems. Soil samples for the study within this dissertation were taken from long-term trial of the Institute of Field and Vegetable Crops at Rimski Šančevi. The trial was set up as three-factorial, and replicated four times, according to the plan of divided plots (split-plot design with randomized variants). The following factors were analysed: 1. Fertilizing systems: single-crop system (control, NPK, NPK+maize remains, NPK+manure) and two-crop rotation – maize/barley (manure, NPK+manure); 2. Soil depth: 0-20 cm; 20-40 cm; 40-60 cm; 3. Maize hybrids: NS 3014; NS 4015; NS 5043; NS 6010; NS 6030. Within the study, phase soil sampling was planned after the maize harvest and during growing period in particular sub-periods of the growing season (2- 3 leaves, 5-7 leaves, silking stage, milk stage). Additionally, plant material was analysed by sampling the first leaf to an ear, as well as yield and morphological traits at the end of growing period. Large number of physical and chemical trait parameters of soil was monitored during the study: mechanical composition, fractionation of structural aggregates, basic chemical characteristics of soil, total and available content of trace elements and heavy metals, content of total phosphorus, content of organic phosphorus, fractionation of inorganic phosphorus for carbonate soils, fractionation of organic phosphorus in the soil, microbiological traits of soil, determination of total macro and trace element amounts in plant material, yield and yield components. Long-term implementation of mineral and organic fertilizers variously affected content of humus and total nitrogen. The content of total organic matter was the highest in the variant of two-crop rotation with manure and mineral fertilizers..

Obzirom da fosfor predstavlja neobnovljiv izvor i čini jedan od glavnih oslonaca moderne poljoprivrede trend globalnih istraživanja kreće se u smeru efikasnije upotrebe fosforovih đubriva, njegovog recikliranja kao i korišćenja alternativnih izvora. Osnova ovih istraživanja zasniva se na praćenju uticaja plodosmene i đubriva (stajnjak, žetveni ostataci i mineralna đubriva), na zastupljenost fosfora i njegovih frakcija u različitim slojevima rizosfere dugogodišnjom primenom određenih sistema gajenja kukuruza. Za predviđena ispitivanja u okviru ove disertacije korišćeni su uzorci zemljišta sa dugogodišnjeg ogleda Instituta za ratarstvo i povrtarstvo na oglednom polju Rimski Šančevi. Ogled je postavljen kao trofaktorijalni, izveden u četiri ponavljanja, po planu podeljenih parcelica (split–plot dizajn ogleda, sa randomiziranim rasporedom varijanti). U istraživanju su obrađeni sledeći faktori: 1. sistemi đubrenja: Monokultura (kontrola, NPK, NPK+kukuruzovina, NPK+stajnjak) i dvopolje - kukuruz/ječam (stajnjak, NPK+stajnjak), 2. dubine zemljišta: 0-20 cm; 20-40 cm; 40-60 cm, 3. hibridi kukuruza: NS 3014; NS 4015; NS 5043; NS 6010; NS 6030. U okviru istraživanja predviđeno je fazno uzimanje uzoraka zemljišta, nakon berbe kukuruza i tokom vegetacije u pojedinim podperiodima vegetacije (2-3 lista, 5-7 listova, svilanje, mlečna zrelost). Takođe izvršeno je i analiza biljnog materijala (uzorkovanje prvog lista do klipa), a na kraju vegetacije izvršena je analiza prinosa i morfoloških osobina. Tokom istraživanja praćen je veliki broj parametara fizičkih i hemijskih osobina zemljišta: mehanički sastav, frakcionisanje stukturnih agregata, sadržaj, osnovna hemijska svojstva zemljišta, ukupni i pristupačni sadržaj mikroelemanata i teških metala, sadržaj ukupnog fosfora, sadržaj organskog fosfora, frakcionacija neorganskog fosfora za karbonatna zemljišta, frakcionacija organskog fosfora u zemljištu, mikrobiološke osobine zemljišta, određivanje ukupnih količina makro i mikroelemenata u biljnom materijalu, prinos i komponente prinosa...