| Abstract | Suša kao prirodna pojava utječe na manjak vlage u tlu te kod biljaka izaziva neki oblik „stresa“, na koje biljke različito reagiraju, što ovisi o genetskim značajkama biljaka, njihovoj razvojnoj fazi, značajkama tla i podneblju. Cilj rada je procijeniti reakciju kukuruza i soje na manjak vode u tlu, odnosno smanjenje prinosa u godini s prosječnom količinom oborina i sušnoj godini na području Orahovice. Za izračunavanje određenih vrijednosti (referentne evapotranspiracije i bilance vode u tlu) korišteni su klimatski podaci s meteorološke postaje (MP) Našice, za razdoblje 2001.-2020. godina. Referentna evapotranspiracija (ETo) izračunata je prema Penman-Montheith metodi, pomoću računalnog programa „CROPWAT“, verzija 8.0.
Efektivne oborine izračunate su prema USDA-SCS metodi. Bilanca vode u tlu za uzgajane usjeve kukuruz i soju izračunata je prema metodi Palmera (korigirana prema Vidačeku 1981.) pomoću računalnog programa „Hidrokalk“. Reakcija kukuruza i soje na manjak vode u tlu i posljedično smanjenje prinosa određena je prema metodi Doorenbos i Kassam.
Nedostatak vode za kukuruz u prosječnoj godini (vjerojatnost pojave oborine - Fa = 50 % slučajeva) na hidromorfnom tlu za vrijeme vegetacije iznosi 141,6 mm, a za soju 128,2 mm. Na hidromorfnom tlu za vrijeme sušne godine (vjerojatnost pojave oborine - Fa = 25 % slučajeva) tijekom vegetacije nedostatak vode za kukuruz iznosi 272,4 mm, a za soju 255,8 mm. Manjak vode za kukuruz u prosječnoj godini na pseudogleju na zaravni tijekom vegetacije iznosi 141,9 mm, a za soju 128,0 mm. U sušnoj godini manjak vode za kukuruz iznosi 277,0 mm, a za soju 260,4 mm. Deficit vode u tlu približno je jednak na oba tipa tla, za obje kulture u godini s prosječnom količinom oborina kao i sušnoj godini na području Orahovice.
Na dreniranom hidromorfnom tlu u prosječnoj godini redukcija prinosa kukuruza je 34 %, soje 25 %, dok je u sušnoj godini redukcija prinosa kukuruza 60 %, a soje 41 %. Na pseudogleju na zaravni u prosječnoj godini redukcija prinosa kukuruza je također 34 %, a soje 22 %, u sušnoj godini redukcija prinosa kukuruza je 61 %, a smanjenje prinosa soje je 41 %.
Za cjelovito rješenje uzgoja kukuruza i soje, kao mogućnost planiranja proizvodnje, nameće se navodnjavanje kao nužna melioracijska mjera, ali i agrotehnički zahvati, kao plodored, gnojidba, obrada tla. |
| Abstract (english) | Drought as a natural phenomenon affects the lack of soil moisture and causes some form of “stress” in plants, to which plants react differently, depending on genetic characteristics of plants, their developmental phase, soil characteristics and climate. The aim of this paper is to assess the reaction of corn and soybean to the lack of water in the soil, i.e. to reduce yields in the year with the average precipitation and dry year in the Orahovica area. For the calculation of certain values (reference evapotranspiration and soil water balance), climatic data from the meteorological station (MP) of Nasaica were used for the period 2001-2020. The reference evapotranspiration (see) was calculated according to the Penman-Montheith method, using the “CROPWAT” software version 8.0. Effective precipitation was calculated according to THE US-SCS method. The soil water balance for cultivated maize and soybean crops was calculated according to the Palmer method (corrected according to Vidacek) using the “Hidrokalk” software. The reaction of maize and soybean to soil water shortages and resulting yield reduction was determined according to the Doorenbos and Kassam methods.
The lack of water for maize in the average year (probability of precipitation - Fa = 50 % of cases) on hydromorphic soil during vegetation amounts to 141.6 mm, for soybean the lack of 128.2 mm. On hydromorphic soil during the dry year (probability of precipitation - Fa = 25 % of cases) during vegetation the lack of water for maize amounts to 272.4 mm, while for soybean 255.8 mm. The water shortage for maize in the average year on the pseudogley on the plateau during vegetation amounts to 141.9 mm, and for soybean it amounts to 128.0 mm. In the dry year, the deficit for corn is 277.0 mm, while for soybean it is 260.4 mm. The water deficit in the soil is approximately the same for both soil types, for both crops in the year with the average precipitation and the dry year in the Orahovica area.
On drained hydromorphic soil, in the average year the reduction of corn yield is 34 %, soybean 25 %, while in the dry year the reduction of corn yield is 60% and soybean 41 %. In the pseudogley on the plateau in the average year, the reduction of corn yield is also 34 %, and soybean 22 %, in the dry year the reduction of corn yield is 61 % and the reduction of soybean yield is 41 %.
Irrigation is imposed as a necessary Melioration but also agro-technical interventions, such as crop rotation, fertilization, soil treatment, for a comprehensive solution and the possibility of production planning. |
