Nutrient Uptake and Yield of Chinese Cabbage (Brassica rapa L. Chinensis) Increased with Application of Macadamia Husk Compost

Abstract

There is a dearth of information on the effect of macadamia husk compost (MHC) on the productivity of short-season, shallow-rooted annual crops. We assessed the response of yield and nutrient uptake of Chinese cabbage (Brassica rapa L. Chinensis) to MHC application. The treatments (zero control, inorganic fertilizer (100:60:60 kg NPK ha−1), and 15 and 30 t ha−1 MHC) were arranged in a randomized complete block design and replicated three times. Number of leaves, leaf area index, leaf biomass, and leaf nutrient concentration (N, P, K, Ca, Mg, Zn, Cu, Mn, and B) were determined at 28, 46, and 74 days after transplanting (DAT), and root length and root biomass were determined at 74 DAT. Inorganic fertilizer and MHC increased root biomass and root length with greater increases recorded at the higher MHC rates. Number of leaves, leaf area index, leaf biomass, and nutrient concentration were greater with application of inorganic fertilizer (28 DAT) and 30 t ha−1 (74 DAT) suggesting that the effect of organic soil amendments is more pronounced over the long run compared with inorganic fertilizers. The concentration of macronutrients in the leaf increased with application of MHC and inorganic fertilizer. Clearly, MHC may be beneficial in improving the leaf yield and nutrient uptake of Chinese cabbage in a loamy sand soil, but the effect varies with time of harvesting.