Modification of the RZWQM2-P model to simulate labile and total phosphorus in an irrigated and manure amended cropland soil

Koehn, A.C. and Leytem, A.B. and Bjorneberg, D.L. (2023) Modification of the RZWQM2-P model to simulate labile and total phosphorus in an irrigated and manure amended cropland soil. Computers and Electronics in Agriculture. 206:1-12. 7 February 2023.

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Abstract

With the expansion of the dairy industry, phosphorus (P)-enriched dairy manure has increasingly been used to replace chemical fertilizer to meet crop nutrient demand. This practice could lead to excessive total P accumulation in the soil and increase the risk of P pollution in the environment. The newly-developed RZWQM2-P model uses the soil P pool structure from the EPIC model, which is not sensitive to total soil P. Therefore, we modified the P module in RZWQM2-P to increase its sensitivity to total soil P. We subsequently assessed the ability of the modified model to simulate labile soil P, total soil P, plant P uptake, and crop yield using a dataset collected from an irrigated field treated with dairy manure and inorganic fertilizer at eight rates. We simulated the long-term soil P dynamics under three P-application scenarios. The results suggested that the modified RZWQM2-P model simulated field-measured annual total soil P, plant P uptake, and crop yield well. Labile soil P was simulated less accurately, but the results were acceptable as the model responded well to P treatments. Long-term simulation results showed that it took 14 years for the labile soil P level to return to the initial level after eight years of manure-P applications at a rate of 65.5 kg P/ha/year. The modified RZWQM2-P model can be used to simulate total soil P and labile soil P contents and to assess P management practices in irrigated cropland amended with manure.

Item Type:	Article
NWISRL Publication Number:	1745
Subjects:	Manure > Chemistry Soil > Amendments Soil
Depositing User:	Users 11 not found.
Date Deposited:	10 Feb 2023 14:35
Last Modified:	10 Feb 2023 14:35
Item ID:	1784
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1784