Növénytermelés / Volume 62 / Issue 3 (September 2013) / pp. 5-22
Examination of the correlations between the water balance and yield of a maize crop stand in different crop rotation systems
The water balance of chernozem soils, as well as its correlation with maize yield were examined in a 30-year long-term experiment in various crop rotation systems (mono-, bi- and triculture) in three crop years with different precipitation supply: drought (2007), rainy (2008) and dry (2009). It can be established from the results that the water stock in all three crop rotation systems and all three crop years decreased significantly (10-15 vol%) in the non-fertilised plots by the end of the growing season. More specifically, the moisture content decreased below the wilting point (16 vol%) in the two dry crop years (10-14 vol% in 2007 and 11-17 vol% in 2009). Based on the 2008 results, the water stock of the soil was favourable (25-30 vol%) for maize in all three crop rotation systems, the wilting point was approached (13-19%) only by the end of the growing season. Pearson’s correlation was used to look for correlations between each crop year and each crop rotation’s yield, water shortage values, irrigation, precipitation before and during the growing season as well as the amount of rainfall in June-July, which is an especially important period from the aspect of water supply. Based on the correlation analysis, it was established that the correlation between precipitation between October and March and water shortage was very strong (-0.768) due the proper water management in the case of the biculture crop rotation system, while the mono- and triculture crop rotation systems are more dependent on the quantity and distribution of precipitation during the growing season. There was a very strong correlation between precipitation during the growing season and water shortage (-0.740, -0.858).
Keywords: long-term experiment, soil moisture, precipitation, irrigation, crop rotation, maize, yield