Effect of a decade-long chemical fertilizers and amendments application on potassium fractions and yield of maize​–wheat in an acid Alfisol

ABSTRACT

Effect of long-term addition of chemical fertilizers with or without amendments was studied on different forms of potassium and the yield of maize and wheat. Continuous application of chemical fertilizers and amendments for 40 years influenced different fractions of potassium significantly. Integrated use of a balanced dose of chemical fertilizer, with farmyard manure (FYM) or lime, sustained higher yields of maize and wheat in comparison to inorganic fertilizers alone. Application of urea (100%) N alone for 40 years resulted in zero yield level. Continuous application of chemical fertilizers either alone or in combination with FYM or lime influenced different fractions of potassium significantly. Continuous cropping without fertilization resulted in depletion to the order of 21.5%, 16.6%, 11.7%, and 5.5% in water-soluble, exchangeable, 0.5 N HCl extractable, and non-exchangeable K, respectively. Different fractions of potassium were found to be positively and significantly correlated with grain and stover/straw yield of maize and wheat.

KEYWORDS:

• Farmyard manure
• lime
• long-term
• potassium fractions and yield

Acknowledgments

The authors feel privileged to thank the Indian Council of Agricultural Research, New Delhi, for providing the financial and technical help to carry out this work through sponsoring the All India Coordinated Project on Long-Term Fertilizer Experiments at CSK Himachal Pradesh Agricultural University, Palampur, HP, India.