Growth and yield of spring cereals during transition to zero tillage on clay soils

Due to the high cost of fuel and labour associated with conventional tillage and because of their advantageous environmental consequences interest in reduced and zero tillage systems has increased Direct drilling into zero tilled (ZT) soil of two spring barley (Hordeum vulgare L) cultivars (six-rowed Rolfi and two-rowed Saana) spring oats (Avena sativa L cultivar Roope) and spring wheat (Triticum aestivum L cultivar Kruunu) was compared with conventional tillage (CT) and drilling into ploughed soil Two field experiments were conducted on clay soils (clay content >50%) between latitudes 60 degrees and 61 N Seed and fertilizer were placed in the same row in ZT and in separate rows in CT Oats was the most productive spring cereal species in ZT Establishment of spring wheat was often poor Barley was most vulnerable to water surplus during early growth and drought during late growth High levels of crop residues caused problems in soil drying in spring and growth of monocultures of oats and wheat A higher seeding rate was advantageous in zero tilled clay soil The substantial grain yield decrease suggests need for improving ZT Long-term trials are required to determine whether ZT suits clay soils as soil structure can change over time and weather conditions play a major role in the productivity of differently tilled soils (C) 2010 Elsevier BV All rights reserved