Nutrient balances: A guide to improving the sorghum- and groundnut-based dryland cropping systems in semi-arid tropical India

Abstract

Information on soil±plant nutrient balance in India and elsewhere is scarce and mostly generalized. A review of earlier studies on nutrient balances was done to assess their relevance for researchers, policy makers, and farmers' understanding, to manage soil fertility for sustainable crop productivity. An on-farm nutrient balance study during 1995/1996 and 1996/1997 was designed to understand nutrient balances resulting from farmers' practices in semi-arid tropical regions of India. This diagnostic study targeted sorghum-based cropping systems and groundnut-based cropping systems in low rainfall areas of the Indian SAT. Selection of farmers for this study was done through a systematic survey and analyses of factors effecting farmers' decision making for nutrient inputs. Intensive plot-speci®c nutrient input and output measurements were carried out on 53 farmers' ®elds for sorghum-based systems and 45 farmers' ®elds for groundnut-based system in this study. Topsoil mineral nitrogen (N) content observed in 2 years at the beginning of the crop season in two locations of Andhra Pradesh, India, was surprisingly high and exchangeable potassium (K) contents also indicated suf®cient supply in most ®elds. Available phosphorus (P) in the majority of ®elds in both locations was around threshold levels, and just suf®cient for most crops. The nutrient balance in sorghum-based systems indicates a moderate to higher negative balance of potassium leading to soil mining for potassium supply in these systems. Nitrogen and P balances were generally positive. Although the groundnut-based system accumulated 53% of its N requirements through BNF, negative balances of N and K were observed mainly due to low applications of these nutrients. Application of K along with options for improving BNF of groundnut are suggested. Better nodulating groundnut cultivars and ef®cient rhizobium strains need to be introduced. High positive balances were observed in the systems whenever commercial crops like castor and cotton were sown in the rotation. This indicates farmers' preferences for applying excess quantities of FYM to commercially important crops even in dryland farming systems. The replenishment costs of mined nutrients annually in different cropping systems were calculated based on current market prices of inorganic fertilizers. #

Phytoextraction of Heavy Metals by two Sorghum Spices in Treated Soil “Using Black Tea Residue for Cleaning-Uo the Contaminated Soil”

“…All necessary precautions were taken to avoid any possible contamination of the sample as per the AOAC guidelines Physical and chemical properties and concentrations of heavy metals ( Chrome, Zinc, lead, Cadmium, Copper, Cobalt and Nickel ) in soils before and after planting sorghum and also after the growth period( in every 10 days ) measured [23][24][25][26][27] . In order to assess amount of heavy metals transfer from soil to plant (shoot and root), translocation factor was determined by dividing metal concentration at shoot by its concentration at root 28 . Different parts of Plant samples (shoots, roots and leaves) were separated and washed and digested by wet method according the standard protocol for measuring Cadmium and Lead.…”

The Effect of Nitrogen and Potassium Fertilizers on Yield and Quality of Sweet Sorghum Varieties under Arid Regions Conditions

“…The high sucrose rate of its stalk is not as much as sugarcane and sugar beet plants, however it has a lower water requirement (40 -50% less water than maize and four times less water than sugarcane), and drought tolerant, meanwhile, its speedy growth rate early ripeness high total energy value addition to, suitable to sub-tropical and temperate region of the world (Martin et al, 1990;Howell et al, 1997 andRego et al, 2003).…”

Widespread Deficiencies of Sulfur, Boron, and Zinc in Indian Semi-Arid Tropical Soils: On-Farm Crop Responses

“…However apart from water shortages, low soil fertility also constrains crop productivity in the SAT regions of India (Rego et al, 2003). Moreover, the use of mineral fertilizers (mostly N and P) is very low in rainfed production systems and most of the fertilizer use is confined to irrigated production systems (Jha and Sarin, 1984;Katyal, 2001).…”

“…Due to low crop productivity in the drylands, it is assumed that mining of micronutrients is much less than in irrigated systems. Rego et al (2003) conducted a study to determine major nutrient balances on 98 farmers' fields (Alfisols) in sorghumand groundnut-based cropping systems in the Indian semi-arid tropics. The balances were negative for N and potassium (K) in majority of farm lands.…”