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.