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

Abstract

<jats:p>Cowpea [<jats:italic>Vigna unguiculata</jats:italic> (L.) Walp.] cover crops were grown in a rotation with broccoli (<jats:italic>Brassica oleracea</jats:italic> L. var. <jats:italic>italica</jats:italic> Plenck.), spinach (<jats:italic>Spinacia oleracea</jats:italic> L.), and turnip greens [<jats:italic>Brassica rapa</jats:italic> L. var. (DC.) Metzg. <jats:italic>utilis</jats:italic>] 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.</jats:p>

Yields and Soil Quality under Transitional Organic High Tunnel Tomatoes

“…Yield (marketable and grade) of tomatoes was initially lower in organically managed high tunnels; however, this difference was insignificant by the second year of organic management. Others have noted that lower application rates of poultry litter were inadequate for maximum production unless the materials were applied repeatedly over several seasons (Alsup et al, 2002;Brown et al, 1994) or composted (Maynard, 1994(Maynard, , 1995. Initial reduction in yield on conversion to organic production is common and is referred to as the ''transition effect'' (Hartz et al, 2000;Scow et al, 1994).…”

Pre-harvest Viral Contamination of Crops Originating from Fecal Matter

“…The other crops also fertilized with manure are barley, cotton, oats, peanuts, sorghum, soybeans, and wheat (USDA 2009). Poultry litter is heavily used as a fertilizer for cotton, peanuts and fresh produce (Alsup and Kahn 2002;Boyhan and Hill 2008), while beef manure is used on more than half of wheat and sorghum farms. Soybeans have been noted to be fertilized by manure from various livestock species.…”

Nitrogen removal from the surface runoff of a field scale greenhouse vegetable production system

“…Ongley et al [9] pointed out that runoff quantity was the key variable in calculating nutrient loading. Previous studies of N runoff in vegetable fields have been mostly based on short-term observations of one crop season, [20][21][22] small plot experiments, [23][24][25][26] monolith lysimeters [27,28], or parameter models. [29,30] Quantifying both runoff volume and N concentration at a field scale could be more accurate in determining N losses.…”