Spring barley growth, grain quality and soil physical conditions in a cultivations experiment on a sandy loam in Scotland

Widely differing cultivations for spring barley, ranging from conventional ploughing to direct drilling and including broadcasting on to undisturbed soil, were examined over two seasons (1979 and 1980), conventional ploughing yielding highest and either chisel ploughing or direct drilling lowest. Yield differences were associated with plant population differences; they were significant only in the abnormally wet season of 1980. Broadcasting before tine cultivation to 50 mm resulted in lower seedbed strength and higher yield than drilling after a similar cultivation. Compaction by the same level of seedbed traffic was greater in a treatment cultivated to 50 mm depth than in the conventional ploughing treatment. Grain milling energy, which is inversely related to endosperm suitability for malting, and grain nitrogen content both decreased with increasing yield. Total nitrogen removed per ha in the grain in 1979 was similar in all treatments (about 72% of applied). In 1980, it was generally lower (about 62% of applied). After allowing for differences in plant populations it was lowest after direct drilling, broadcasting and very shallow tine cultivation (60% of applied), highest after conventional ploughing (70% of applied) and intermediate after rotary cultivating and shallow tine cultivation (65% of applied). Soil water release characteristics were described by logistic equations. Treatment differences were greatest at matric potentials greater than -3 kPa at 10 and 60 mm depth. The porosities of the cultivated soils were similar to each other, and were greater than those of the direct drilled treatments.