Effect of irrigation on pseudogley structural composition in the protected cultivation

Abstract

Pseudogley soils are very important in agricultural production thanks to their significant percent cover, potential fertility, the fact that they occur in predominantly flat soil complexes, suitable for mechanized tillage. Moreover, it could be the substrates for protected cultivation. Intensive multiannual production in plastic greenhouses causes the changes which lower the soil productivity as well as changes soil structure. The aim of this paper is to investigate the degree to which pseudogley structure is changed by vegetable production in plastic-covered greenhouses, in the conditions of intensive irrigation and fertilization. The six-year-long implementation of drip irrigation system caused some changes in the soil structural composition in the sense of a mild increase in the content of larger-sized aggregates (>5mm), but also their greater liability to decomposition, as well as a mild decrease in the percentage of water-stable aggregates larger than 1mm. The soil water logging in the plastic greenhouse led to elevated processes of structure deterioration, the formation of crumby aggregates, as well as to the decrease in water stability of structural aggregates.

Pseudoglejna zemljišta imaju veliki značaj za poljoprivrednu proizvodnju zbog njihove značajne zastupljenosti, potencijalne plodnosti, činjenice da se javljaju na pretežno ravnim kompleksima zemljišta pogodnim za primenu mehanizovane obrade, kao i mogućnosti da se koriste kao podloga za proizvodnju u zaštićenim prostorima. Tokom intenzivne višegodišnje plasteničke proizvodnje dolazi do promena koje smanjuju produktivnu vrednost i dovode do promene strukturnog sastava zemljišta. Cilj ovog rada bio je da prouči u kojoj meri plastenička povrtarska proizvodnja, u uslovima intenzivnog navodnjavanja i đubrenja utiče na promenu strukture pseudogleja. Šestogodišnja primena navodnjavanja sistemom kap po kap dovela je do izvesnih promena u strakturnom sastavu zemljišta smislu blagog povećanja sadržaja agregata većih dimenzija (većih od 5mm.), ali i njihove veće sklonosti prema rasplinjavanju, kao i blagog smanjenja sadržaja vodootpornih agregata većih od 1mm. Prevlaživanje zemljišta u plasteniku dovelo je do izraženih procesa kvarenja strukture, stvaranja grudvastih agregata, kao i smanjenje vodootprnosti strukturnih agregata.