Effect of Rice Straw Biochar on Soil Quality and the Early Growth and Biomass Yield of Two Rice Varieties

Abstract

Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion (particularly on the uplands). One possible approach to addressing the soil constraints to rice production both on uplands and lowlands of Sierra Leone is the recycling of rice residues through biochar production and application to soils. A pot experiment was conducted to investigate the effects of application of biochar from rice residues on (i) soil physicochemical properties and (ii) the early growth characteristics of two rice varieties, NERICA L19 and ROK3. The experiment was arranged in a completely randomized design (CRD) with two biochar levels (0 and 15 g/kg soil) and two rice varieties in three replications. For the biochar treated soils (+biochar), 75 g rice straw biochar was applied to 5 kg air-dry soil (15 kg biochar/kg soil), mixed thoroughly and placed into perforated black polythene bags. Seeds of two rice varieties, NERICA L19 and ROK3 were planted on the treated and untreated soils for eight weeks. Application of biochar improved available phosphorus, exchangeable cations and cation exchange capacity in biochar treated soils compared to the control soil without biochar. Plant height, tiller number, and dry biomass weight of both rice varieties grown in soils amended with rice straw biochar were significantly higher than those on untreated soils. The most remarkable increase in plant growth characteristics as a result of biochar addition to soil was reflected in the biomass yield and tiller numbers. Dry shoot biomass for ROK3 rice variety varied significantly from a mean of 3.5 g (control) to 26.2 g (+biochar) while tiller numbers significantly varied from 10 (control) to 29.6 (+biochar). Similarly, for NERICA L19 rice variety, dry shoot biomass increased significantly from 4.5 g (control) to 22.7 g (+biochar) while tiller numbers increased significantly from a mean of 12.3 (control) to 30 (+biochar). Thus converting rice residues to biochar and applying to soil holds

The influence of rice husk and tobacco waste biochars on soil quality

“…This is in line with Kamara et al (2015) who reported that application of rice husk biochar improved soil properties by increasing soil pH, organic carbon, and available nutrients. Biochar application to soils improves soil alkalinity and increases the soil pH, even though not all biochars are alkaline.…”

Effect of plant residues derived biochar on fertility of a new reclaimed sandy soil and growth of wheat (Triticum aestivum L.)

“…Agegnehu et al (2015( indicated that higher maize growth after application of willow biochar as compared with acacia biochar might be illustrated by its larger effect on nutrient retention capacity, pore spaces and nutrients supplement for maize plants. Kamara et al (2015( found that incorporation of rice straw to infertile soil had remarkable influence on rice shoots and roots and their dry weights were higher at 5 g biochar kg -1 soil than at the control (0 g kg -1 (. Moreover, they mentioned that the improvement of soil physicochemical properties in response to biochar addition could be used to reflect the higher rice growth in poor fertile soil.…”

Potentials of Rice Straw, Rice Hull and Saw Dust on the Growth and Yield Performance of Rice Grown Under Variable Moisture Conditions in Saline Soil

“…The lowest plant heights (73 cm in moist and 77 cm in saturated condition) were recorded in the control condition (RH 0 RS 0 SD 0 ). Kamara et al (2015) reported that rice plants grown on soils treated with rice straw were significantly (p < 0.05) taller than those grown on soils without treatment. Incorporation of rice straw into the soil combined with cattle manure gave the maximum plant height (Parham et al 2002).…”