Effects of crop species and applied N on soil moisture

Abstract

A neutron probe was used to measure soil moisture under crops of spring barley, wheat, oats, cocksfoot, Italian ryegrass and perennial ryegrass in each of 2 years and under barley, sugar beet, potatoes, field beans, white clover and perennial ryegrass in each of 2 years. All crops were sown in April. Two levels of applied N, 0 and 150 kg N ha −1 were compared. Spring beans were the tallest and highest yielding crop and used most water in the later stages of growth. Spring barley, wheat and oats used much water in the earlier stages of growth, but not subsequently. Sugar beet and potatoes developed slowly in terms of soil moisture use. The forage grasses and white clover continued growth up to the date of harvest and used quite a large amount of water relative to the yield harvested. The application of N increased the yield of the non-legume crops, but not that of the legumes. The application of N increased the water use of the non-legume crops, but not that of the legumes, in 1987 and 1988, but not in all cases in 1984 and 1985.