Improvement of soil properties, nutrient availability and wheat traits induced by the addition of organic materials: A field study

Recently, intensive farming systems entailing abundant use of chemical fertilizers have deteriorated agricultural soils and contributed to environment pollution which necessitates testing organic amendments. The objectives of the present multi-year study were to investigate the impact of different soil organic amendments i.e. humic acid (HA) and molasses (Ms) applied at 0.25 and 0.50% (v/w) on soil properties and to find out optimum application level for maximizing growth and yield of wheat. The results showed that soil bulk density (BD) and total porosity were significantly improved with the application of Ms applied at 0.50% as compared to HA application. In both growing seasons, the relative change in field capacity (FC) and wilting point (WP) due to the application of Ms in the surface layer at 0.50% were increased by 14% and 33.13, respectively over the control. The corresponding values of HA were 25.40 and 27.84%, respectively than the control. The increase in nitrogen availability was more pronounced with the application of Ms than HA application, while the opposite was true for available phosphorus (P) and potassium (K). The maximum plant height was observed with a lower rate of HA, which was 16.59% more than the control. The application of Ms at higher rate was superior in increasing the grain and straw yield which were 35.39 and 113.01%, respectively more than the control treatment. The grain N, P, and K contents were increased by 19.13, 69.57, and 56.98% with the application of a higher rate of HA. Thus, it is concluded that the application of organic amendments hold potential to improve physicochemical and hydrological properties of soil which ultimately trigger growth, yield, and nutrient accumulation in wheat.