Investigating the effect of conservation tillage methods on organic matter and energy indices in bean cultivation (Case study of Arak city)

This study aimed to investigate the effects of conservation agricultural methods on the amount of soil organic matter, energy indices, and crop yield in white bean (Dorsa variety) cultivation. The experiment was conducted in a randomized complete block design with three replications at the Markazi Agricultural and Natural Resources Research and Education Center in the cropping years of 2017-2018, 2018-2019, and 2019-2020. The experimental treatments were involved: 1- the conventional tillage method (by using moldboard plow+ disc) as a control, 2-Reduced tillage with a chisel-packer plow, and 3-No-tillage method with a direct planting seeder. In each season, the soil organic matter content was measured. The yield and yield components of dry bean seeds were measured at the end of the season by removing the margins. In addition, inputs and outputs energy consumption, gross energy produced per hectare, energy ratio and intensity, and energy productivity were calculated for each treatment. The results showed that the highest and lowest yields were obtained in reduced tillage and no-tillage, respectively, with 2869 and 2076 kg/ha. The three-year average values of soil organic matter in the experimental treatments for each season were 0.430, 0.582, and 0.621%, respectively, with the highest increase seen in reduced tillage treatment. The highest and the lowest energy intensity were obtained for no-tillage and reduced tillage with 38.6 and 27.3 MJ/kg, respectively. One of the reasons for increasing energy consumption and decreasing the yield in the no-tillage method was the high weed population and plentiful consumption of general and specific herbicides. Finally, due to the increase in grain yield, amount of soil organic matter, and improvement of energy indices in dry bean cultivation, the reduced tillage method was evaluated as more suitable than the no-tillage method.