|Han, Ming -|
|Zhang, Li -|
|Fan, Chong -|
|Liu, Li -|
|Zhang, Lin -|
|Li, Bing -|
Submitted to: Soil Science and Plant Nutrition (SSPN)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 31, 2011
Publication Date: August 26, 2011
Citation: Han, M.Y., Zhang, L.X., Fan, C.H., Liu, L.H., Zhang, L.S., Li, B.Z., Alva, A.K. 2011. Release of nitrogen, phosphorus, and potassium during the decomposition of apple (Malus domestica) leaf litter under different fertilization regimes. Soil Science and Plant Nutrition (SSPN). 57:549-557. DOI: 10.1080/00380768.211.593481. Interpretive Summary: In perennial cropping systems, i.e. fruit trees example apple trees, annual shedding of leaves upon decomposition and subsequent mineralization contribute nutrients for growth and production in the following year. The rate of decomposition of leaf litter in an apple orchard and release of N, P, and K over a 24 month period were investigated in this study. Leaf litters used in this study were collected from trees fertilized at recommended, low, and high NPK rates. The decomposition of leaf litter evaluated by weight loss method followed an exponential decay model for all 3 litter samples. The leaf litters from high NPK fertilized trees released greater amounts of N and P as compared to those of leaf litters collected from trees that received either recommended or low rates of NPK. The average amounts of N, P, and K released from leaf litters were equivalent to 10, 6, and 58% of the respective nutrient requirements during the first 12 months, respectively, and 63, 6, and 8% in the next 12 months period. This study demonstrates estimates of recycling of nutrients from leaf litters are important to consider while developing annual nutrient requirements. This step will minimize excess application of fertilizers that may lead to nutrient losses from the orchards.
Technical Abstract: The decomposition of apple (Malus domestica) leaf litters has a pivotal role in nutrient release in orchard ecosystems. We have studied the decomposition rate and subsequent release of nitrogen (N), phosphorus (P), and potassium (K) nutrients over 24-months using litterbags method. From three types litter received different rates of N, P, K fertilization (control, CK; low fertilizer rate, LF; and high fertilizer rate, HF) . The patterns of mass loss of all three litters were quite similar followed the exponential decay model. However, the amount of mass loss was greater for HF and LF litters than that for CK litter over the first 6 months. During the initial 6 months, concentrations of N and P in the leaf litters increased while that of K declined. Subsequently, concentrations of all elements decreased during 24-month of incubation. The release of N and P from leaf litter was positively correlated to the respective concentrations in the leaf litter at the beginning of decomposition. The amounts of N and P release from the litter were greater for that collected from the trees which recieved HF than that under CK and LF treatments. The rapid release of K occurred during the early stage across all litters and was not influenced by varying levels of leaf nutritional status. At the end of 24 months of decomposition, the relative release of nutrients from litters followed the order: K > N > P. The mean quantities of N, P, and K released during the first and second year following the application of 10, 6, 58% and 63, 6, 8% of recommended rates at respective nutrients for young apple orchards in Loess Plateau. Therefore, the results suggest that nutrient release from leaf litter in an apple orchard system can contribute a significant portion of the nutrient requirement for apple production. Accounting for this nutrient contribution in the annual fertilizer management is important to avoid excess application, optimize net returns, and maintain sustainable production systems.