Impact of primary soil tillage intensity on maize (Zea mays L.) seedbed formation and productivity parameters

Abstract

In condition of balanced mineral fertilization the decrease of soil tillage intensity (from deep ploughing to shallow loosening with cultivator) decreased energy consumption and positively affected its balance. The demonstrational field trials were carried out on a silty loam soils at the Experimental Station of Lithuanian University of Agriculture (Kaunas reg.) and agricultural farm “Grūduva” (Šakiai reg.) in 2003. The aim of investigations was to establish the influence of primary soil tillage intensity on maize seedbed formation, productivity parameters and energy balance of technologies. In both trials soils were deep ploughed (20-22 cm) with a mouldboard plough “Kverneland” in autumn (control treatment), also shallow loosened with cultivator “Horsch” (5-8 cm, Experimental Station) or disc harrow “Kuhn” (10-12 cm, farm) in autumn. According to the results of investigations, the decrease of primary soil tillage intensity had positive influence on maize seedbed moisture content (up to 20-26% in seedbed surface and up to 9-17% in seedbed down) and structural compositions, therefore these influenced on denser crop formation (up to 0.7-0.9 plants m-2). The highest maize productivity parameters were found in the crop of 80 thousand plants per ha but this increased tillering of stems. The increase of crop density up to 120-125 thousand plants per ha decreased average mass of kernels, number of kernels per row of cob and yield of grain. Tillering of stems was not found. In condition of wellbalanced even mineral fertilization the decrease of soil tillage intensity had no influence on maize productivity parameters. Organic fertilization was more effective in autumn than in spring, especially in conditions of minimal soil tillage. Organic fertilization of maize increased (by 30-35%) input of energy; however, total balance of energy was similar in both tillage conditions because of yield difference.