Soil Physico-Chemical Properties and Crop Yield Improvement Following Lantana Mulching and Reduced Tillage in Rainfed Croplands in the Indian Himalayan Mountains

Abstract

In the rainfed crop fields of the Central Himalayan Mountains in India, low soil moisture and low soil fertility are the two major constraints on crop yield. Therefore, an experiment was conducted to test the hypothesis of whether mixing a high-quality (high foliar N, P, and K and low lignin) organic residue (Lantana camara leaves) with the relatively low-quality leaf litter of oak (Quercus leucotrichophora) and pine (Pinus roxburghii) forests, and then mulching the organic residue, would enhance the rate of organic residue decomposition and nutrient release to contribute to the soil fertility and crop yield of wheat and paddy in rainfed crop fields. To achieve the study objectives, Lantana residue was mixed with oak and pine leaf litter in four different proportions and applied under three tillage frequencies in 36 experimental plots in a completely randomized block design. These four mulch combinations were also studied for dry matter decomposition and nutrient release pattern. Results showed that both the decomposition rate (k = 1.86 yr−1) and rate of nutrient release from decomposing litter (N = 0.208 mg d −1 and P = 0.042 mg d −1) for Lantana residue were much higher than the other litter combinations. Mixing Lantana with other mulch materials positively influenced the decomposition and nutrient release of otherwise slow decomposing oak and pine leaf litter. The 100% Lantana mulched plots recorded substantially higher soil moisture among the four mulching treatments. The 100% Lantana mulched plots also recorded significantly higher soil nutrients (NO3 +-N and PO4 −-P under wheat and NH4 +-N under rice crops) and rate of N-mineralization, and produced significantly higher wheat grain (920 to 1309 kg ha−1) and wheat and rice straw yield than the conventional practice of crop cultivation. Lantana residue thus proved to be a potential mulch to achieve soil moisture conservation, soil fertility enhancement, and higher crop yields in the region.