Nutrient uptake and removal by sweet potato fertilized with green manure and nitrogen on sandy soil

Abstract

Sweet potato crops take up large amounts of nutrients, especially nitrogen. In low-fertility soils, the addition of nitrogen (N) increases the sweet potato yield. Green manure may be an alternative method for improving soil quality and supplying nutrients to this crop. This study aimed to evaluate the plant's nutritional status and the amount of nutrients taken up and removed by sweet potato plants subjected to green manure and mineral N fertilization. The experiment was carried out in the field for two growing seasons using a randomized block design in a split-plot scheme with four replications. The plots consisted of a control treatment (spontaneous weeds) and the previous cultivation of Crotalaria spectabilis and Mucuna aterrima. The subplots consisted of four N rates (0, 50, 100, and 200 kg ha -1 ) that were applied to the sweet potato. The species M. aterrima is more suitable for use as green manure in the sweet potato than C. spectabilis. Nitrogen application rates promoted a greater increase in the biomass of the storage root, nutrient uptake, and removal in the sweet potatoes unfertilized with green manure. In the sweet potato fertilized with M. aterrima, mineral N supply in excess (above 50 kg ha -1 ) increases the nutrient uptake and removal without a significant increase in the biomass of the storage root. In the sweet potatoes unfertilized with green manure, high rates of N (greater than 120 kg ha -1 ) must be applied to obtain the utmost biomass of the storage root, nutrient uptake and removal.

Nitrogen Dynamics and Sweet Potato Production under Indigenous Soil Moisture Conservation Practices in the Leeward Kohala Field System, Hawai’i Island

“…However, appreciating the low input farming system and environmental factors, the crop's efficiency to use N can be enhanced through strategized nutrient management. A strong, positive correlation between cumulative inorganic N to SPAD measurements indicates that plant productivity can be improved increasing N availability [49]. Understanding crop nutrient needs, N rates and sources, placement methods, the timing of application, irrigation management, and residue management can affect N uptake and its efficiency of use.…”

Productivity, quality, and nutrient uptake of intensive forage crop rotations based on corn in sandy soil (northern Morocco)

“…However, the rainfed forage crops could develop low biomass in a dry winter season that could serve as green manure to incorporate into the soil. The green manure supply in sandy soil could help to enhance the organic matter and the nitrogen level (Fernandes et al, 2020;Roper et al, 2012;Saleh, 2013). The forage cropping system based on one corn cycle (berseem-corn-soybean) had the lowest yield (30.8 t ha -1 year -1 ).…”

Sweetpotato responses to potassium rate and timing in tropical sandy soils

“…Sweetpotatoes take up high amounts of K (Fernandes & Ribeiro, 2020; Fernandes et al., 2020), which is essential for proper nourishment and root yield. In this study, plants grown in soils with low and medium exchangeable K and without K fertilization showed deficient K concentrations in the leaves (<31 g kg −1 ; Lorenzi et al., 1997), which did not occur in soil with initial high exchangeable K, demonstrating that K already available in the soil must be considered in the recommendation of K fertilization for sweetpotatoes.…”