Root Phenotyping of Wheat under Different Soil Compaction Levels in Two-Contrasting Soils of India

Soil compaction is an increasingly challenging worldwide problem for crop production and an important issue in the field of soil management. Soil compaction influences root system that affects water and nutrient acquisition. In modern agricultural production systems, increase in a number of passes and the loads by agricultural machinery leads to soil compaction and affects crop productivity. However, the crop-root systems remain as an unexplored target for improvements of crop yields and productivity. Wheat is one of the most important cereal crops of India as well as of the world. Globally, India is the second largest producer of wheat with approximately 92 million tonnes with the highest area of 30.6 million ha amongst all the wheat-producing countries in the world. In this study, we investigated interactive effects of wheat root system architecture (RSA) and soil compaction levels in two contrasting soils of India. A three weeks laboratory study was carried out in rhizo tubes of size 25 cm height and 5 cm diameter with four replications. Soil types considered in this investigation were Inceptisols and Alfisols. The levels of bulk density (BD) chosen for this experiment were (i) 1.2 (B1), (ii) 1.4 (B2), (iii) 1.5 (B3) and (iv) 1.6 (B4) Mgm^-3. The RSA parameters such as root depth, number of nodes, number of primary axis, length of primary axis, root-angle root diameters, root surface areas and root volume were obtained to understand the dynamic of root system under different soil compaction levels. Results indicated that wheat crop grown at the higher BD exploited smaller soil volumes and exhibited reductions in root surface area, total root volume, and total root length, but had a greater mean root diameter than at lower BD in both soils. It was further observed that wheat RSA parameters, performing better in Inceptisols than Alfisols.