Long-term effect of residue management on soil physical properties, water use and yield of rice in North-Western India

Destruction of aggregates and damage to soil structure during puddling for lowland rice cultivation makes it difficult to bring the soil back to its original condition during the following upland crop. Besides, this type of rice cultivation consumes enormous amount of water, labour and energy. Field experiments were conducted at the experimental farm of Himachal Pradesh Agricultural University, Palampur, India (32°6′ N, 76°3′ E; altitude 1300 m above msl) for twelve years starting from the wet season of 1988 to study the effect of four levels of lantana (Lantana camara L.) residue incorporation [0 (M0), 10 (M1), 20 (M2) and 30 (M3) Mg ha⁻¹ and three levels of nutrients on soil physical properties, water use and yield of rice. Soils of the study area are classified as Typic Hapludalf with pH 5.6, organic carbon 6.6 g kg⁻¹ and cation exchange capacity 12 cmol(p⁺)kg⁻¹. After twelve annual additions of lantana residue, water stable aggregates increased significantly (P = 0.05) at 20 and 30 Mg ha⁻¹ levels compared to control. However, bulk density values decreased significantly with an accompanying increase in total porosity at all levels of lantana addition compared to control. The available water capacity increased by 3–6 per cent by the addition of different levels of lantana. Resistance to penetration decreased with an increase in lantana addition, the energy required to plough different plots also decreased (5.14 to 2.98 GJ ha⁻¹) with the highest rate of lantana addition as compared to control. Addition of lantana @ 10, 20 and 30 Mg ha⁻¹ increased rice yields by 17.5, 23.4 and 30 per cent, respectively, over control. The trend analysis indicated that the rice yields were maintained under control as well lantana-amended plots. Also, the improvement in physical properties would also favourably affect the succeeding upland wheat crop.