Viljelusviisi mõju kartulimugula toitainetesisaldusele

Abstract

Üha enam eelistatakse mahevijeluse teel toodetud kartulit ja sellega seoses on vaja uurida, et milline viljelusviis on selleks parim. Töö eesmärgiks oli uurida erinevate viljelussüsteemide mõju tärklisesisaldusele, toitainetesisaldusele ja nitraatide sisaldusele ning kuidas mõjutab viljelussüsteem kartuli saaki. Antud uurimustöö katse viidi läbi Eesti Maaülikooli Põllumajanduse- ja keskkonnainstituudi Rõhu katsejaama Eerika katsepõldudel, kus kartul on üks kultuur 5-väljalisest külvikorra katsest. Käesolevas töös kasutati aastal 2017 kogutud katseandmeid. Katses uuriti tavaviljeluse (4 erinevat) – ja maheviljelusviise (3 erinevat) mõju kartulikasvatusele. Kõik katsed olid neljas korduses. 4 tavaviljeluse süsteemi erinesid üksteisest antavate lämmastiku normide poolest: N0 (N0P0K0); N1 (N50P25K95); N2 (N100P25K95); N3 (N150P25K95). Maheviljeluse süsteemid olid M0 – maheviljeluse kontrollsüsteem, M1 – maheviljelusesüsteem, kus kasvatati lisaks talviseid vahekultuure, M2 – maheviljelusesüsteem, milles kasutati samuti talviseid vahekultuure ning lisaks anti kartulile kevadel orgaanilist sõnnikut normiga 20 t ha-1 . Enim saaki andis N3 variant (58 t ha -1 ) ja vähima saagikusega oli M0 (28,3 t ha-1 ). Lämmastikväetiste kasutamine suurendas nitraatide ja lämmastikusisaldust mugulas ja vähendas tärklise osakaalu kartulis. Tärklise protsent oli suurem maheviljeluses (MI 20,5%). Antud katses ei mõjutanud erinevad viljelusviisid fosfori ja kaaliumi sisaldust mugulas. Mineraalväetiseid kasutades saab suurema saagi, kuid maheviljeluse teel kasvatatud kartuli koostis on kvaliteetsem.

The popularity of organically produced potato is increasing rapidly and due to that, it is important to find out the best farming system. The aim of the current study was to investigate the effect of different cropping systems on the content of starch, nutrient and nitrate of the potato tubers as well as yield. The experiment was carried out at the Estonian University of Life Sciences on the Erika test site of Rõhu experimental station in 2017. There were five crops in rotation including potato. The experiment included 4 conventional and 3 organic farming systems. All tests were in 4 replications. 4 conventional farming systems were different regarding the application rate of the mineral nitrogen as follows: N0 (N0P0K0); N1 (N50P25K95); N2 (N100P25K95); N3 (N150P25K95). The organic farming systems were as follows: M0 – organic control system, M1 – organic farming system, which included winter cover crops, M2 – organic farming system, which included winter cover crops and the potato was fertilized with organic manure (20 t ha-1 ) in the spring. The highest yield was in the conventional system N3 (58 t ha-1 ) and the lowest was in the organic system M0 (28,3 t ha-1 ). The application of nitrogen fertilizers enhanced the nitrate and nitrogen concentration and reduced starch content in tubers. The percentage of starch was higher in organically grown potatoes (MI 20,5%). The results revealed that the farming systems did not have any significant effect on the concentration of phosphorus and potassium in the potato tubers. Higher yield comes from the use of mineral fertilizers but the quality of the potato tuber is better under organic system