Mulberry nutrient management for silk production in Hubei Province of China

Abstract

The silk industry is important for south China's rural economy. Leaves of mulberry (Morus spp.) are used for silkworm production. Hubei province is one of the main silk‐producing provinces in China. The objectives of this research were to survey the fertilization practices in the mulberry‐producing regions in the province and to determine the best nutrition‐management practice for mulberry plantations. A survey and a series of field experiments with N, P, K, and micronutrients were conducted from 2001 to 2002. In addition, a silkworm‐growth experiment was also conducted by feeding leaves harvested from various fertilization treatments. The results indicate that poor soil fertility and unbalanced fertilization were the main factors limiting mulberry‐leaf yield and quality in Hubei province. Nitrogen fertilization of mulberry has reached a high level (454 kg ha–1 y–1) in Hubei province, but P‐ and K‐fertilization rates have not been matched with N‐fertilization rates as farmers are not aware of the significance of P and K. Balanced fertilization showed positive nutrient interactions with respect to mulberry yield and quality. Potassium application increased yield and quality (protein and sugar concentration) of mulberry leaves. Silkworm growth and cocoon quality were improved when silkworms were fed with the leaves derived from K‐fertilized plants in comparison with those taken from control plots. Application of Mg, S, and B also significantly improved leaf sugar, essential and total amino acid concentrations, but did not increase leaf yield significantly. It is concluded that a fertilizer dose of 375 kg N ha–1, 66 kg P ha–1, and 125 kg K ha–1 is suitable for the cultivation of mulberry in the Hubei province along with Mg, S, and B, wherever necessary, for the improvement of yield and quality of mulberry leaves.

Changes in Silk Feedstock Rheology during Cocoon Construction: The Role of Calcium and Potassium Ions

“…Subsequently, the rise in the concentration of monovalent cations (i.e., K + ) would displace some of the divalent ions from the carboxylate salts and increase electrostatic screening around anionic groups, reducing the amount of interchain bridging and lowering the viscosity. If correct, this mechanism represents a chemically simple method by which the silkworm can alter the viscosity of the feedstock, by controlling the ion concentration in the gland via its own ion‐transport proteins, using species abundant in its foodstuff (mulberry leaves) …”

Soil Nutrient Assessment for Urban Ecosystems in Hubei, China

“…In the land south of the Yangtze River, farmers need to add K fertilizer for high yields [31]. However, the concentration of available K (125 mg kg -1 ) in urban soil of this region was found to be moderate, slightly higher than the rural average of 79.3 mg kg -1 [14].…”

Response of Bacteria Community to Long-Term Inorganic Nitrogen Application in Mulberry Field Soil

“…However, the leaf yields of mulberry in Hubei Province which is one of the main silk-producing regions in China are about half lower than those in other leading silk-producing provinces, such as Guangxi, Guangdong and Zhejiang [15]. A previous survey suggested that fertilizer application has become an important factor that limits leaf yield and quality in Hubei province [15]. In order to obtain large quantities of leaves, farmers often use inorganic fertilizers, particularly nitrogen fertilizers.…”

“…In order to obtain large quantities of leaves, farmers often use inorganic fertilizers, particularly nitrogen fertilizers. Currently, nitrogen fertilizers are applied to mulberry plantations at the high rate of 454 kg N ha –1 y –1 in Hubei Province [15]. However, few studies have investigated the effects of this high input level on the changes in soil microbial community composition and diversity [16–17].…”