Kartuli saagikus ja kasvatamise tasuvus sõltuvalt viljelusviisist

Abstract

Antud uurimustöö eesmärgiks oli välja selgitada, kuidas mahe- või tavaviljelus mõjutavad mugulate saaki 2016. aastal ning kui suurt mõju avaldavad nimetatud viljelusviisid saagi kvaliteedile ja kartuli kasvatamise tasuvusele. Külvikorra katse viidi läbi Eerika põllul Eesti Maaülikoolis. Katses oli 4 tavaviljelussüsteemi ning 3 maheviljelussüsteemi. Neli tavaviljeluse süsteemi erinesid üksteisest lämmastiku normide poolest: N0 (N0P0K0); N1 (N50P25K95); N2 (N100P25K95); N3 (N150P25K95). Maheviljeluse süsteemid olid järgnevad: M0 – maheviljeluse kontrollsüsteem; M1 – maheviljelusesüsteem, kus kasvatati talviseid vahekultuure; M2 – maheviljelusesüsteem, milles kasutati talviseid vahekultuure ning lisaks anti kartulile kevadel ka täielikult komposteerunud allapanuga veisesõnnikut normiga 20 t/ha. Suurima kartulisaagi andis tavaviljeluse variant N3 (58,6 t/ha), kus kasutati võrreldus variantidest kõige suuremat N kogust (150 kg N/ha). Seega, mida rohkem anda kartulile lämmastikväetist, seda suurem on saak. Kõige väiksem nitraatide sisaldus oli kartuli mugulates, mis olid kasvatatud maheviljelus variantides, tavaviljeluse variantides lisades lämmastikväetist nitraatide sisaldus suurenes. Kõige suurem tärklise sisaldus kartuli mugulates oli maheviljeluse variandis M2 (18%). Lämmastikväetise kasutamine vähendas kartuli mugulas tärklise sisaldust. Enim positiivset mõju avaldas kartuli tärklise sisaldusele sõnniku kasutamine ja vahekultuuride kasvatamine. Kartuli kasvatamiseks kõige rohkem kulutusi tehti variandis M2 (4 072,4 €/ha) ning suurimat kasumit teeniti samuti maheviljeluse variandis M2 (17 130,6 €/ha). Suur kasum maheviljeluses oli tingitud 2016. aasta kõrgest mahekartuli müügihinnast.

The objective of the given thesis was to explore how organic or conventional farming affect the crop yield of tubers in 2016 and how big of an influence they have on the quality of the crops and the profitability of potato growing. Crop rotation study took place in Eerika field at Estonian University of Life Science. The experiment was performed with four conventional and three organic farming systems. Four conventional farming systems were differed from each other in the amounts of fertilizers which used as follows: N0 (N0P0K0); N1 (N50P25K95); N2 (N100P25K95); N3 (N150P25K95). Three organic farming systems were as follows: Organic M0 – Organic control system; Organic M1 – were used winter catch crops; Organic M3 – were used catch crops and also fully composted cattle manure (20 t/ha) was added as a fertilizer. The biggest crop yields came from conventional farming (58,6 t/ha), where the larger amounts of fertilizer were used (150 kg N/ha) comparated to the ohter treatments. Thus, the more nitrogen fertilizer is used on potatoes, the larger the crop yields. Potato tubers from organic farming systems have a smaller amount of mitrates. In conventional farming systems the amount of nitrates in tuber increased with the added nitrogen amount. The largest amount of starch in potato tubers was in the M2. Using nitrogen fertilizer decreases the amount of starch in potato tubers. The most positive influence on potato starch content was caused by the manure and catch crops. The biggest expenses for growing potatoes were made in the M2 version (4 072,4 €/ha) and the largest profit was also made in the M2 version (17 130,6 €/ha). A big profit came from organic farming systems because in September 2016, the sale price of organic potatoes was high.