Biochar affects growth and shoot nitrogen in four crops for two soils

Abstract

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.

Biochar for Wastewater Treatment and Soil Improvement in Irrigated Urban Agriculture: Single and Combined Effects on Crop Yields and Soil Fertility

“…The elevated SOC, pH, CEC, and direct nutrient addition by biochar might have reduced nutrient immobility in the soil, increasing mass flow for nutrient uptake. Tissues analysis of lettuce and carrot grown on biochar-amended soil by Olszyk et al (2020) also revealed an improved macronutrient in their tissues. In a related study, Deenik et al (2010) indicated a slight increase in crop tissue Na, Fe, and Mn concentrations induced by biochar addition to the soil.…”

Nutrient Dynamics in Sandy Soil and Leaf Lettuce Following the Application of Urea and Urea-Hydrogen Peroxide Impregnated Co-Pyrolyzed Animal Manure and Bone Meal

“…Contrary to what Gunes et al [53] observed, Rees et al [54] reported increments in Zn content in the Cd-Zn hyper accumulator plant called Noccaea caerulescens grown on alkaline soils amended with biochar, whist the amendment on acidic soils reduced Zn accumulation. Rees et al [54] employed heavy metals-contaminated soils and the decrease in leaf Zn content was probably due to an increase in soil pH with addition of biochar, especially for a strongly acidic soil [51]. It should be noted that our soil was not strongly acid (CaCl 2 pH of 5.7), which may explain why the NEBs fertilizers and BC elicited increases in soil pH actually led to increases in Zn contents in the leaf lettuce.…”

“…The high Zn contents of both the co-pyrolyzed biochar and BC might have ensued from the contamination by the galvanized metal containers used for charring, as O'Toole et al [49] suggested. Additionally, Zn is usually used as a supplement in animal feeds [50], and indeed, Olszyk et al [51] found high Zn concentrations (5000 to 6800 ppm) in their swine solids biochar even though the Zn content of the lettuce leaves was not increased upon that biochar application. However, Gartler et al [52] found no statistically significant differences between the zinc contents of the leaf lettuce grown on the control and biochar-amended soils, despite the fact that the amount of zinc in the leaf lettuce grown on the latter were higher than those of the control experiment.…”

“…Similarly, Ramzani et al [57] found increases in essential nutrients in the quinoa seeds with sulphur-acidified biochar. Olszyk et al [51] found that animal manure-based biochars decreased Ca, Mg, and Zn contents in the leaves of lettuce and carrot taproots even though the decreases were smaller in the latter than in the former. The increments registered for all the micronutrients of the leaf lettuce grown under the amendments of pyrolyzed materials might have been due to three main reasons namely; direct supply of nutrients, changes in soil pH and reduction of the dilution effect.…”

The Occurrence of Legacy P Soils and Potential Mitigation Practices Using Activated Biochar

“…Moreover, biochar with particle sizes <1 mm can increase water conservation in sandy soil more than larger (1–2 mm) particle sizes [ 103 ]. As a result, designer biochar applied to nutrient-poor soils have been reported to increase soil fertility properties [ 104 – 106 ] and improve crop growth [ 107 – 109 ].…”