Effects of simplified cultivation on the growth and yield of spring barley on a sandy loam soil. 2. Soil physical properties and root growth; root: shoot relationships, inflow rates of nitrogen; water use

• Published in: Soil & tillage research 1992, Vol.22 (1), p.173-187
• Main Authors: Braim, M.A., Chaney, K., Hodgson, D.R.
• Format: Article
• Language: English
• Subjects: ABONOS NITROGENADOS; APPLICATION EN LIGNE; ARADURA; AZOTE; CERO-LABRANZA; COMPACTACION DEL SUELO; COMPACTAGE DU SOL; CRECIMIENTO; CROISSANCE; CROP YIELD; CULTIVATION; CULTIVO; DRILLING; ENGRAIS AZOTE; GROWTH; HORDEUM VULGARE; LABOUR; LOAM SOILS; NITRATE; NITRATES; NITRATOS; NITROGEN; NITROGEN FERTILIZERS; NITROGENO; NON TRAVAIL DU SOL; OPERACION DE CULTIVO EN LINEAS; PLOUGHING; POROSITE DU SOL; PRATIQUE CULTURALE; PROPIEDADES FISICO-QUIMICAS SUELO; PROPRIETE PHYSICOCHIMIQUE DU SOL; RACINE; RAICES; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; ROOTS; SANDY SOILS; SISTEMA POROSO DEL SUELO; SOIL CHEMICOPHYSICAL PROPERTIES; SOIL COMPACTION; SOIL PORE SYSTEM; SOL SABLEUX; SOL SABLOLIMONEUX; SUELO ARENOSO; SUELO FRANCO; USO DEL AGUA; UTILISATION DE L'EAU; WATER USE; ZERO TILLAGE
• ISSN: 0167-1987; 1879-3444
• DOI: 10.1016/0167-1987(92)90030-F

Spring barley was established on a sandy loam soil by direct drilling and after shallow cultivation or mouldboard ploughing for a period of 3 years (1978–1980). In 1980, growth studies were carried out on these treatments without nitrogen (N) fertilizer and with 150 kg N ha −1. There were no significant differences between the three soils in bulk density, total pore space or air capacity, but penetrometer measurements after direct drilling showed cone resistances in the topsoil to be 7–9 times greater than those after ploughing. For shallow cultivation, cone resistances < 10 cm were similar to those for direct drilling. With N fertilizer, direct drilling and shallow cultivation reduced final root length by 33 and 15%, respectively, compared to ploughing, but differences in the dry mass of root were much smaller. Dry weight per unit length of root was greatest for direct-drilled barley. Final shoot dry mass was depressed ≈20% by direct drilling and 10% by shallow cultivation. That soil compaction affected the partitioning of dry matter was shown by the lower ratio of shoot: root during most of the season for direct-drilled barley. Differences in the final uptake of N between cultivations were non-significant, although throughout growth direct-drilled barley took up less N than barley on the other treatments due to a lag in uptake initially. Maximum inflow rates of N per unit length of root were 2.5 times greater for direct-drilled barley than for barley after ploughing, thus compensating for a shorter root length. The cultivation system did not affect water use by the crops. It was concluded that in direct-drilled soil a slower release on nitrate from organic matter during early growth was the likely cause of reduced yield.