Integrated use of biochar and compost to improve soil microbial activity, nutrient availability, and plant growth in arid soil

Abstract

Soil amendments, such as compost and biochar are known to affect soil properties, soil microbial activity, and plant growth. These organic amendments have the ability to increase soil fertility, carbon sequestration, and crop productivity. However, there is limited information available on the integrated application of biochar and compost on microbial and enzymatic activity, nutrients availability and plant growth in arid soil. The present study was designed to quantify the effect of biochar along with compost on soil microbial biomass (carbon, nitrogen, phosphorus), enzyme (urease, alkaline phosphatase, dehydrogenase) activity, nutrients (N, P, K) availability in soil, and plant growth. The treatments comprise a control, biochar at 20 g kg−1 soil, compost at 20 g kg−1 soil, biochar + compost at (10 g kg−1 soil + 10 g kg−1 soil), biochar + compost at (15 g kg−1 soil + 5 g kg−1 soil), and biochar + compost at (5 g kg−1 soil + 15 g kg−1 soil). Tomato was grown as a test plant in the pot experiment. The results revealed that biochar and compost alone or in combinations proved statistically significant for Soil pH. Application of biochar at 20 g kg−1 soil proved useful and increased (130%) microbial biomass carbon (MBC) as compared with control. Compost at 20 g kg−1 soil increased alkaline phosphatase (143%), urease activity (10%) and plant nitrogen (33%) over control. However, microbial biomass nitrogen (MBN), and dehydrogenase activity increased by 62, and 100% respectively in the treatment receiving biochar and compost at 10 + 10 g kg−1 soil compared to that in the control. Plant phosphorus and potassium contents were 34 and 70% higher in the treatment receiving biochar and compost at 5 + 15 g kg−1 soil than in the control. However, for plant parameters (plant height, plant fresh weight, and plant dry weight), the combination of biochar and compost at 15 + 5 g kg−1 soil was superior to other treatments.