Biochar application rate affects biological nitrogen fixation in red clover conditional on potassium availability (original) (raw)
Related papers
Biochar affects growth and shoot nitrogen in four crops for two soils
Agrosystems, Geosciences & Environment, 2020
To address the need for information on biochar effects on crop growth and nitrogen (N), a greenhouse study was conducted with carrot, lettuce, soybean, and sweet corn using sandy loam (Coxville series) and loamy sand (Norfolk series) soils and a variety of biochars. Biochar was produced from pine chips (PC), poultry litter (PL), swine solids (SS), switchgrass (SG), and two blends of PC plus PL (50/50% [55] and 80/20% [82], wt/wt), with each feedstock pyrolyzed at 350, 500, or 700˚C. The results confirmed that biochar can increase crop growth; however, the responses varied with crop, soil, and feedstock and to a lesser extent with pyrolysis temperature. In general, lettuce had large increases in shoot and root dry weights vs. no-biochar controls with many biochars, primarily the SS and 55 blend and to a lesser extent with 82 followed by PL, and then PC and SG, especially when grown in the Coxville soil. Biochar had more limited effects on carrot, sweet corn, and soybean weights. Some biochars decreased crop growth (e.g., PL at 700˚C) for soybean shoot and pod dry weights with the Norfolk soil. Shoot N concentrations decreased with SS, 55, and 82 for carrot, lettuce, and sweet corn with the Norfolk soil but tended to increase for soybean. Shoot N uptake increased or decreased depending on biochar feedstock and temperature, crop, and soil. These results confirm that biochar can increase crop growth and affect shoot N, which is essential for crop growth.
international journal of biosciences , 2019
The rapid growth and degradation of soil fertility and quality of human and industrial operations. The fertility of the land to improve the sustainability and yield of the crops is a major concern for the rehabilitant. Biochar is the carbonated material generated from biomass and used to enhance soil fertility by maintaining the nutrients and possibly improving bioavailability of the nutrients. Biochar is not a straightforward, homogeneous carbohydrate material so that an appropriate biochar choice is deemed a target cultivation and soil type. This led to the reporting of numerous research evaluating different techniques of modification, such as optimizing pyrolysis procedures, blending with a number of other soil amendments, compositing with a number of other additives and activating physicochemical procedures, in order to maximize biochar efficacy. Nevertheless, it cannot be overlooked the financial importance of biochar feasibility. This review shows the current understanding and implementation with economic aspects of the holistic and practical approaches for the application of biochar to less fertile soil.
Applied Sciences
The available literary data suggest the general applicability and benefits of different biochar products in various soil–plant–environment systems. Due to its high porosity, biochar might generally improve the physicochemical and biological properties of supplemented soils. Among the direct and indirect effects are (i) improved water-retention capacity, (ii) enhanced soil organic matter content, (iii) pH increase, (iv) better N and P availability, and (v) greater potential uptake of meso- and micronutrients. These are connected to the advantage of an enhanced soil oxygen content. The large porous surface area of biochar might indirectly protect the survival of microorganisms, while the adsorbed organic materials may improve the growth of both bacteria and fungi. On the other hand, N2-fixing Rhizobium bacteria and P-mobilizing mycorrhiza fungi might respond negatively to biochar’s application. In arid circumstances with limited water and nutrient availability, a synergistic positive ...
Biology and Fertility of Soils, 2012
The effects of biochar properties on crop growth are little understood. Therefore, biochar was produced from eight feedstocks and pyrolyzed at four temperatures (300°C, 400°C, 500°C, 600°C) using slow pyrolysis. Corn was grown for 46 days in a greenhouse pot trial on a temperate and moderately fertile Alfisol amended with the biochar at application rates of 0.0%, 0.2%, 0.5%, 2.0%, and 7.0% (w/w) (equivalent to 0.0, 2.6, 6.5, 26, and 91 t biochar ha −1 ) and full recommended fertilization. Animal manure biochars increased biomass by up to 43% and corn stover biochar by up to 30%, while food waste biochar decreased biomass by up to 92% in relation to similarly fertilized controls (all P<0.05). Increasing the pyrolysis temperature from 300°C to 600°C decreased the negative effect of food waste as well as paper sludge biochars. On average, plant growth was the highest with additions of biochar produced at a pyrolysis temperature of 500°C (P < 0.05), but feedstock type caused eight times more variation in growth than pyrolysis temperature. Biochar application rates above 2.0% (w/w) (equivalent to 26 t ha −1 ) did generally not improve corn growth and rather decreased growth when biochars produced from dairy manure, paper sludge, or food waste were applied. Crop N uptake was 15% greater than the fully fertilized control (P<0.05, average at 300°C) at a biochar application rate of 0.2% but decreased with greater application to 16% below the N uptake of the control at an application rate of 7%. Volatile matter or ash content in biochar did not correlate with crop growth or N uptake (P>0.05), and greater pH had only a weak positive relationship with growth at intermediate application rates. Greater nutrient contents (N, P, K, Mg) improved growth at low application rates of 0.2% and 0.5%, but Na reduced growth at high application rates of 2.0% and 7.0% in the studied fertile Alfisol.
Environment International , 2016
‘Biochar’ represents an emerging technology that is increasingly being recognized for its potential role in carbon sequestration, reducing greenhouse gas emissions, waste management, renewable energy, soil improvement, crop productivity enhancement and environmental remediation. Published reviews have so far focused mainly on the above listed agronomic and environmental benefits of applying biochar, yet paid little or no attention to its harmful effects on the ecological system. This review highlights a balanced overview of the advantages and disadvantages of the pyrolysis process of biochar production, end-product quality and the benefits versus drawbacks of biochar on: (a) soil geochemistry and albedo, (b) microflora and fauna, (c) agrochemicals, (d) greenhouse gas efflux, (e) nutrients, (f) crop yield, and (g) contaminants (organic and inorganic). Future research should focus more on the unintended long-term consequences of biochar on biological organisms and their processes in the soil.
Biochar Application in Soil Management Systems
Biochar - Productive Technologies, Properties and Application [Working Title]
Due to its potential for improving soil fertility and reducing greenhouse gas emissions, biochar is frequently used as a soil amendment. This chapter presents an overview of its application and soil conditioning mechanisms as a technique for long-term carbon sequestration and lower greenhouse gas emissions, as well as an option for improving soil fertility. It focuses on biochar amendment for improved soil properties that support plant nutrient uptake and crop yield improvement, soil properties and biochar carbon sequestration dynamics, biochar degradation processes, and soil interactions and conditioning mechanisms that influence biochar carbon stability in soils. Current biochar stability assessment techniques used in academic studies are also addressed, along with their suitability for use with various goals and situations.
Biochar , chemical characterization , nutrient effects , dynamics and preliminary plant growth tests
2016
Four commercial grade biochar were evaluated as peat substitute. We characterised these biochars for plant nutrients and for biological stability. The results showed that there were negligible quantities of N and P and generally high levels of K and high biological stability. When these materials were mixed with peat at 10, 25 and 50 % and nutrients were added to bring them to the same level of nutrients as in fertilized peat, it was found that biochar mixes considerably reduced the levels of calcium chloride/DTPA (CAT) extractable N (including nitrate), P, and electrical conductivity– greater extent with higher rates of biochar addition except for K. Generally there was increase in pH and reduction of EC and extractable nitrate, ammonium and EC The drop in EC has important implications regarding the use of other materials used to dilute peat, for example, composted green waste as the rate of dilution is limited due to high EC and biochar addition gives the potential for higher peat...