Changes on phosphorus fractions and paddy yield using different single super phosphate and rock phosphate rates under acid soil

Abstract

Agricultural soils are usually deficient in phosphorus (P), causing yield reduction. To boost crop production and P availability in acid soil, rock phosphate (RP) can be used with single super phosphate (SSP), which can also supply available P for the long-term during a crop cycle. The study was conducted to show the effect of SSP and rock RP on the P release and fixation pattern and its uptake by paddy variety CAU-R1 in acid soil. The experimental design was randomized block design having six treatments, where P supplied through i) only SSP, ii) only RP, iii) 3/4^th SSP + 1/4^th RP, iv) half SSP + half RP, v)1/4^th SSP + 3/4^th RP and vi) control. The addition of P in general increased all inorganic P forms with time over untreated control. There was an increase in saloid-P, Aluminum-P, Iron-P, Calcium-P, and available P concentration reaching maximum on 50^th day with gradual decline till harvest. Phosphorus application significantly increased P uptake, dry matter yield, tiller number, and plant height of paddy during the entire growth period. Comparatively higher P uptake and grain yield were observed in soil applied with SSP and RP at 1:1, as SSP predominantly supplied P at the earlier growth stage and RP released P slowly. Therefore, the combined use of SSP and RP at 1:1 can provide a constant pool of available P and improve agronomic efficiencies under acid soil.

Keywords:

• Paddy yield
• phosphorous fractions
• rock phosphate
• single super phosphate
• soil phosphorous

Authorship contribution statement

Sudip Sarkar: conceptualization, methodology, formal analysis, investigation, data collection, visualization, and writing—original draft. N Surbala Devi: experimentation and revision. Rogers Wainkwa Chia: supervision, writing—review and editing, final draft. Morad Mirzai: revision and final editing. Arjan Reijneveld: supervision and writing—review and editing. Mario Fontana: Supervision, Writing – review and editing. Kai-Jiun Lo: supervision, writing—review and editing.

Acknowledgments

We are thankful to Department of Soil Science and Agricultural Chemistry, Central Agricultural University, Imphal, India for providing all the necessities during the whole research period. We are grateful to Judith Nyiraneza of Agriculture and Agri-Food Canada (Charlottetown, Canada) for her overall guidance in draft preparation, editing and final review.

Disclosure statement

No conflict of interest was reported by the authors.

Additional information

Funding

No funding sources are available.