Title

Using Cowpea to Manage Soil Phosphorus Accumulation from Poultry Litter Applications in a Cool-season Vegetable Rotation

Abstract

Cowpea [Vigna unguiculata (L.) Walp.] cover crops were grown in a rotation with broccoli (Brassica oleracea L. var. italica Plenck.), spinach (Spinacia oleracea L.), and turnip greens [Brassica rapa L. var. (DC.) Metzg. utilis] to evaluate the legume's ability to remove excess P from soils when poultry litter was used as a fertilizer. Fertilizer treatments were: 1) litter to meet each crop's recommended preplant N requirements (1×); 2) litter at twice the recommended rate (2×); and 3) urea at the 1× rate as the control. Following the vegetable crops, cowpeas were planted on half of each replication, while the other half was fallowed. The cowpeas were harvested at the green-shell seed stage and then underwent a simulated haying operation to remove remaining shoot material from the field. Soil samples were taken at 0-15 cm and 15-30 cm depths at the onset of the study and after each crop to monitor plant nutrient concentrations. The cowpeas lowered soil test N concentrations at both soil sampling depths, but had no consistent effect on soil test P concentrations. Soil test P at the 0-15 cm depth was not increased by litter at the 1× rate but was increased by litter at the 2× rate relative to the urea control, regardless of cropping system. Poultry litter was effective as a fertilizer for all three vegetable crops, but the 1× rate appeared inadequate for maximum production of broccoli and turnip greens.

Department(s)

Environmental Plant Science and Natural Resource

Document Type

Article

DOI

https://doi.org/10.21273/hortsci.37.3.496

Rights Information

HortScience is an open-access publication that adheres to Creative Commons licensing: CC BY-NC-ND 4.0. You may share, copy and resdistribute this material for non-commercial purposes in any medium.

Publication Date

2002

Journal Title

HortScience

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