Nutrient and water balances in lysimeter experiments. I. Barley yields, water use and water balances.

摘要

The relationship between barley yield and water balance was investigated in weighing lysimeters with 4 soils from agricultural areas in Norway, 2 water regimes and 4 nutrient treatments. Irrigation, applied at 100 mm per season, increased barley yield at all fertilizer levels in the dry years of 1993 and, in particular, 1992, but only at the highest rate of fertilizer application (16 g N/m2) in 1990 and 1991. The evapotranspiration (May-October) increased and drainage losses decreased by respectively 10 and 8 mm per 100 g/m2 increase in grain + straw yield. Evapotranspiration of added water increased from 10% at the lowest fertilizer rate (3 g N/m2) in 1990 to 95% at the highest fertilizer rate in 1992. Increased drainage was responsible for the rest. The increased drainage after irrigation in May-July was delayed to rainy periods in October. There were fairly small differences in evapotranspiration, drainage and effect of irrigation between soils.