Sulfur fertilization enhanced productivity and profitability of popular kenaf varieties

Kenaf, also known as Deccan hemp (Hibiscus cannabinus L.) is the one of the most important, hardy and economic bast fiber industrial crops. Sulfur plays a significant role in determining yield and quality of fiber crops. However, the effect of sulfur application on yield, nutrient uptake in kenaf varieties, agronomic efficiency, apparent S recovery, and nutrient availability and sulfur fractions is still unclear. Thus, the present investigation was carried out to study the effect of sulfur (S) fertilization (S-0= Control, S-15=15kg S ha(-1), S-30=30kg S ha(-1), S-45=45kg S ha(-1)) on fiber yield, nutrient uptake, nutrient availability and S fractions of experimental soil and to screen the kenaf varieties ('JBM-2004-D', 'MT-150', 'AMC-108' and 'HC-583') for higher S use efficiency and increased productivity. Compared to control (S-0), S-45 treatment significantly increased fiber yield of kenaf by 37%. MT-150 produced the highest fiber yield (2.61 t ha(-1)). Among the S levels, S-45 exhibited lowest value of agronomic efficiency (16.5 kg kg(-1) S), apparent S recovery (18.7%) and highest value of nutrient uptake in kenaf. Results also revealed that nutrient availability (nitrogen, phosphorus and potassium) increased with increase in S levels at all soil depths and the nutrient status decreased with depth. Sulfur fractions (total S, organic S, adsorbed S, plant available S) increased with increasing S levels and followed the order as organic S > non-sulfate S > adsorbed S > plant available S. In addition, organic sulfur contributed 63-74% of total sulfur. Thus, the results suggest that by selecting appropriate variety and level of sulfur (@ 30 kg ha(-1)) for kenaf cultivation farmers can obtain higher fiber yield for sustainable crop production.