Influence of Biochar Mixed into Peat Substrate on Lettuce Growth and Nutrient Supply

Abstract

The use of peat in traditional cultivation systems and in commercial nurseries is an environmental problem. In this work, we evaluated the partial replacement of peat with different amounts of biochar sourced from vineyard pruning as plant growing substrates. We studied its effect on the growth of lettuce plants under greenhouse and semi-hydroponic conditions. Substrate mixtures contained 30% (v/v) of vermiculite and 70% (v/v) of different biochar:peat treatments as follows: 0:70 (B0), 15:55 (B15), 30:40 (B30), 50:20 (B50), and 70:0 (B70). Higher biochar treatments increased the pH and electrical conductivity of the substrate, negatively affecting plant growth and germination (especially in B70). The partial substitution of peat by 30% biochar (B30) delayed seed germination but improved plant growth and nitrogen use efficiency (NUE), with shoots containing higher levels of organic nitrogen and nitrate. Moreover, it increased the water holding capacity (WHC) and led to an efficient use of nutrients. Our study demonstrates that biochar can successfully replace and reduce peat and N fertilizer consumption. This has the potential to promote more sustainable farming with positive impacts on both plant growth and the environment.

Effect of Shading, Substrate, and Container Size on Argania spinosa Growth and Cost–Benefit Analysis

“…Plants in S6 were rich in total nitrogen compared to S1. This is in accordance with the results of an experiment conducted by García-Rodríguez et al [102], who concluded that the N element in lettuce leaf increased with the increase in the quantity of biochar used. The S6 (with 50% biochar) analysis mainly showed a higher salinity and Na concentration, but this amount did not affect argan plant growth.…”

“…The substrate treatment study for the argan tree revealed two growth medias that can be a substitute to peat moss in high quantities. Knowing that peat moss releases a higher atmospheric emission and is currently limited due to a high demand, which has caused a deterioration of the peatland ecosystem [100], the use of alternative substrates would be beneficial for resource-saving and as sustainable and recyclable resources [101,102]. Biochar, which is made from the thermochemical conversion of waste biomass, has a great capacity for carbon sequestration [103].…”