Evaluation & Development of Cultivation Techniques of Rainfed Maize + Sweet Potato Inter-Cropping under Indian North-Western Himalaya

Abstract

Maize (Zea maize L.) is grown for human food, animal fodder, and chicken feed in India's Northwestern Himalayan Region (NWHR), which covers over 0.33 million hectares of cultivated land. In the NWHR of India, substantial soil erosion is a major challenge in maize production, resulting in low rainfed maize productivity. During the peak rainy season in NWHR, a single maize crop can only cover up to 30% of the land, leaving more bare soil vulnerable to soil erosion. Furthermore, sole maize growing only generates roughly Rs. 30,000-40,000 in net income per hectare field, making maize farming less profitable for farmers. Using a randomized block design with four replications, a field experiment was conducted with five treatments: maize-wheat (control), maize + sweet potato-wheat, maize + colocasia-wheat, maize + ginger, and maize + turmeric to conserve soil and water, increase crop productivity, and farmers profit by introducing soil conserving and high-value crops with rainfed maize cultivation. The authors discussed the developed scientific rainfed maize + sweet potato (Ipomoea batatas [L.] Lam) intercropping technique in NWHR, which had not before been devised for this region. From 8.7 t ha^-1 soil loss of sole maize, maize + sweet potato intercropping can minimize it to 1.5 t ha^-1 and increase maize grain yield to 3.5 t ha^-1 from 3.1 t ha^-1. In addition to higher maize production, the system also produced 5.0-7.0 t ha^-1 of fresh sweet potato tubers. Thus, intercropping of maize + sweet potato under NWHR can reduce soil erosion while also enhance maize yield and farmers' profit in rainfed conditions.