Greenhouse Evaluation of Pinewood Biochar Effects on Nutrient Status and Physiological Performance in Muscadine Grape (Vitis rotundifolia L.)

Abstract

Muscadine grape is a perennial crop that is highly responsive to local environmental factors and viticulture practices. Biochar is a promising soil amendment used to improve soil water and nutrient retention and promote plant growth. The present study aimed to assess the effects of different pinewood biochar rates on nutrient status and vegetative parameters of muscadine grape cv. Alachua grown on a nutrient-poor sandy soil, Ultisols (97.2% sand, 2.4% silt, and 0.4% clay), and mixed with five different rates (0%, 5%, 10%, 15%, and 20%) of biochar based on weight. Variations in soil moisture, temperature, and leaf greenness value [soil plant analysis development (SPAD) reading], net photosynthesis rate, and plant root and shoot dry weights were measured. In addition, the nutrient status of the soil, plant root, and shoot were determined. The results indicated that the higher rate of biochar could significantly (P < 0.05) improve soil moisture. Biochar can also decrease soil temperature, although there were no significant differences among treatments. Regarding the nutrient status, the biochar amendment increased the nutrient content of phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca), as well as the soil organic matter content and cation exchange capacity. Higher nutrient contents in soil lead to increased P and Mg in both aboveground and belowground muscadine plant tissues and decreased nitrogen (N), iron (Fe), and copper (Cu) in the root part. There were no significant differences observed in SPAD values, net photosynthesis, or dry weights of the root and shoot. This study demonstrates that the addition of biochar may enhance the soil water and nutrient status as well as improve plant P and Mg uptake; however, it showed no significant differences in the physiological performance of muscadine grape plants.