Nutrient loads and sediment losses in sprinkler irrigation runoff affected by compost and manure

Lehrsch, G.A. and Lentz, R.D. and Westermann, D.T. and Kincaid, D.C. (2014) Nutrient loads and sediment losses in sprinkler irrigation runoff affected by compost and manure. Journal of Soil and Water Conservation. 69(5):456-467.

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Abstract

High water application rates beneath the outer spans of center pivot sprinkler systems can cause runoff, erosion, and nutrient losses, particularly from sloping fields. This study determined runoff, sediment losses, and loads of nutrients (dissolved organic C, Nitrate-N, ammonium-N, total phosphorus [TP], ferric-oxide strip phosphorus [FeO P], dissolved reactive phosphorus [DRP], K, Ca, Mg, and Na) in sprinkler runoff for two years after a single application of either stockpiled or composted dairy manure. The two-year field investigation studied five treatments, including a non-amended control, in each of six blocks, with each block situated under a different span of a moving-lateral sprinkler system. In October 1999, we incorporated 29.1 or 71.7 Mg/ha of dry manure or 22.4 or 47.0 Mg/ha of dry compost into a calcareous silt loam soil on slopes from 0.8% to 4.4%. In spring of 2000 and 2001, we collected surface soil (0 to 5 mm) from bed tops to determine aggregate stability by wet-sieving field-moist aggregates and surface soil (0 to 30 mm) from furrows to determine soil test phosphorus (STP). We applied 21 to 46 mm of water at an average application intensity of 28 mm/h (peak intensity of 40 mm/h) to 6.4- x 36.6-m field plots six times in 2000 and twice in 2001. Additional non-monitored irrigations were made as needed to produce corn (Zea mays L.) silage each year. We measured runoff rates and collected 1-L runoff samples at 15- to 30-minute intervals to determine sediment and constituent losses for each monitored irrigation. None of the amendment treatments significantly affected runoff, sediment losses, or loads of dissolved organic C, ammonium-N, or TP. Without exception, runoff, sediment losses, and loads of every measured constituent varied among irrigations, after accounting for differences in water applied. Treatments influenced DRP, K, and Ca runoff loads, with DRP loads being 5 to 6 times greater from the manure treatments than the control. Loads of Nitrate-N, DRP, and Na were 2- to 4-fold greater from plots amended with manure rather than compost.

Item Type:	Article
NWISRL Publication Number:	1515
Subjects:	Irrigation > Sprinkler irrigation Manure > Composted manure Manure > Runoff
Depositing User:	Dan Stieneke
Date Deposited:	05 Dec 2014 18:09
Last Modified:	05 Dec 2014 18:10
Item ID:	1559
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1559