Viljelusviiside mõju talinisu umbrohtumusele ja saagile

Abstract

Nisu on üks enam kasvatatavaid teravilju. Eestis kasvatatakse järjest rohkem nisu nii tavakui ka maheviljeluses. Maheviljeluses on probleemiks nisu umbrohtumus ja seetõttu väheneb saak ja halveneb saagikvaliteet. Uurimistöö eesmärgiks oli uurida viljelusviisi mõju talinisu umbrohtumusele ja saagile kolmes erinevas maheviljelussüsteemis (M0, M1, M2) ja neljas tavaviljelussüsteemis (N0, N1, N2 ja N3). Katse rajati 5 väljalise külvikorrana, süstemaatilise plokksüsteemina, kus kultuuride järjestus oli järgmine: Oder punase ristiku allakülviga – punane ristik – talinisu – hernes – kartul. Talinisu umbrohtumust mõjutas eelviljana kasvatatud punase ristiku survetõrje. Punase ristiku kasvatamine odra allakülvina suurendas tavaviljeluses umbrohtumust nendes süsteemides, kus kasutati mineraalväetist. Tööst ilmneb, et maheviljeluses on talinisu umbrohtumus suurem, kui tavaviljeluses. Tavasüsteemis mineraalse lämmastikuga väetatud variantidelt saadi statistiliselt usutavalt suuremad saagid võrreldes mahesüsteemidega. Talviste kattekultuuride kasvatamine külvikorras (M1) või talviste kattekultuuride ja sõnniku koosmõju (M2) ei andnud usutavat saagilisa võrreldes kontrollsüsteemiga (M0). Nisu tera saaki ja 1000 tera massi suurendasid mineraalse lämmastikuga väetamine ja taimekaitse.

Wheat is one of the most growth cereals. In Estonia wheat is grown in an increasing number in both conventional and organic farming. Weediness in wheat is a problem in organic farming and thus decreasing yield and degrade the quality of yield. The aim of the reasearch was to study the weediness and yield of winter wheat in three different organic farming systems (M0, M1, M2) and in four conventional farming systems (N0, N1, N2, N3). The experiment was set up on five-field crop rotation in systematic block system, where crops had the following sequences: Barley undersown with red clover – red clover – winter wheat – pea – potato. Weed infestation in winter wheat was affected by red clover, grown as intermediate crop, pressure control. In barley undersown with red clover in conventional farming systems the weed infestation was increased, where mineral fertilizers were used. The experiment shows that in the organic farming systems the weediness of winter wheat was higher than in the conventional farming systems. In conventional system, where mineral nitrogen fertilization was used, variants showed statistically significantly higher yields compared to organic systems. Growing winter cover crops in rotation (M1) or winter cover crops and manure interaction (M2) did not have a significantly higher yield compared with the control system. Wheat grain yield was positively affected by thousand grain weight. In this trial fertilizing and plant protection increased the thousand grain weight.