Affiliation:
1. São Paulo State Univ. (UNESP), Center of Tropical Roots and Starches (CERAT) Lageado Experimental Farm P.O. Box 237 18610‐307 Botucatu São Paulo Brazil
2. São Paulo State Univ. (UNESP), College of Agricultural Sciences Botucatu São Paulo Brazil
Abstract
Core Ideas
Legumes improved N supply for sweet potato grown subsequently.
Mucuna aterrima supply more N to sweet potato than other cover crops.
Previous legume cultivation reduces 35.2% the mineral N rate on sweet potato.
Higher mineral N rate increased growth of sweet potato vines.
Selected cover crops can provide N to sweet potato (Ipomoea batatas [L.] Lam) crops cultivated in succession and reduce the need for mineral N application. This study was conducted to determine the growth, leaf N concentration, N uptake, N removal, storage root yield, and N‐use efficiency of sweet potato crop in response to different cover crop sources and mineral N fertilizer rates. A field experiment was performed over 2 agricultural yr using a randomized complete block design with split‐plots and four replications. Whole plots consisted of four cover crops: One control (spontaneous weeds), two legumes (Crotalaria spectabilis and Mucuna aterrima), and one cereal (Pennisetum glaucum). Subplots consisted of four N rates (0, 50, 100, and 200 kg ha−1) applied to the sweet potato. When no N was applied, M. aterrima supplied more N to sweet potato grown in succession but had the same effect as C. spectabilis on root yield. P. glaucum and spontaneous weeds had the same effect on the N supply and performance of sweet potato. The N rates for the optimum root yield of sweet potato were 49.6 and 76.6 kg N ha−1 when grown after legume and non‐legume species. In tropical conditions, the use of legumes as cover crops reduced the need for mineral N fertilizers by up to 35.2% for sweet potato. The cultivation history of a field should be an important consideration when determining the N fertilization for sweet potato because a high N supply favored the growth of vegetative plant parts.
Funder
Fundação de Amparo à Pesquisa do Estado de São Paulo
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Cited by
14 articles.
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