1. Agbenin JO, Felix-Henningsen P (2004) Dynamics of copper fractions and solubility in a savanna soil under continuous cultivation. Nutr Cycl Agroecosyst 68:117–125
2. Babita. 2010. Nitrogen dynamics in soil-plant system as influenced by long-term use of chemical fertilizers and amendments in an acid Alfisol. M Sc Thesis. Department of Soil Science, CSKHPKV, Palampur, India. pp 120
3. Bajpai RK, Chitale S, Upadhyay SK, Urkurkar JS (2006) Long-term studies on soil physico-chemical properties and productivity of rice-wheat system as influenced by integrated nutrient management in inceptisols of Chhattisgarh. J Indian Soc Soil Sci 54(1):24–29
4. Behera SK, Singh D (2009) Effect of 31 years of continuous cropping and fertilizer use on soil properties and uptake of micronutrients by Maize (Zea mays)-wheat (Triticum aestivum) system. Indian J Agric Sci 79(4):264–267
5. Behera SK, Singh D, Dwivedi BS, Bhadraray S (2009) Fractions of copper availability and uptake by maize-wheat cropping sequence. J Plant Nutr 32(7):1092–1107