Nitrate accumulation and movement under deficit irrigation in soil receiving cattle manure and commercial fertilizer

Abstract

Nitrate leaching from agricultural soils can increase groundwater nitrate concentrations. The objectives of the study were to assess the accumulation and movement of nitrate in the soil profile over a 2-year period under deficit irrigation conditions following a one time application of N in cattle feedlot manure and commercial fertilizer to corn at rates to achieve yield goals expected under conditions of full irrigation. Cattle manure and ammonium nitrate were applied in 2002 at the University of Nebraska recommended rate (1M and 1F, respectively) and cattle manure was applied at twice the recommended rate (2M) for N for the 2002 corn (Zea mays L.) crop. The recommended rate was based on expected yields under full irrigation. The manure N treatments were applied to percolation lysimeters and adjacent plots on a Cozad silt loam soil. Ammonium nitrate was applied only to the percolation lysimeters. Leachate from the lysimeters was extracted from a depth of 2.1 m and soil samples were collected from field plots in 0.3 m depth increments to 2.1 m on a periodic basis. Water available to the crop was sufficient to meet 89 and 79% of the potential crop ET in 2002 and 2003, respectively. When averaged over the manure N treatments, reduced ET resulted in grain yields that were approximately 2.1 and 2.7 Mg ha −1 less than ex- − -N ha −1 ). Nitrate-N mass increased in the 0.9-2.1 m soil depth 12-13 months after manure N treatment applications. The 2M treatment had greater soil NO 3 − -N mass than the 1M treatment for most sampling dates in the surface 0.9 m. This research shows that there can be significant nitrate losses under deficit irrigation when manure N is over applied. These losses are likely related to water initially stored below the root zone and preferential flow of water from irrigation and precipitation. Determining accurate yield expectations under deficit irrigation conditions, correct scheduling of irrigation, and the use current best management practices for N management can help minimize nitrate losses in leachate.

Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system

“…In addition to the N uptake pattern, the irrigation regime during the different seasons determined soil N min levels in the rooting zone and had a large effect on N fertilizer recommendations. Low irrigation rates were applied during the later fruiting period in the AW season in contrast to the WS season, and this would have reduced the risk of nitrate leaching out of the root zone and therefore unavailable for crop growth during irrigation (Nakamura et al, 2004;Tarkalson et al, 2006). N supply strategies during the AW seasons are therefore distinct from those in the WS seasons.…”

Nitrogen- and phosphorus-based applications of cattle manure and compost for irrigated cereal silage

“…Other studies have shown that crop yields generally are similar between manure and synthetic fertilizers when applied to meet crop N requirements (Stevenson et al 1998;Eghball and Power 1999b;Basso and Ritchie 2005;Tarkalson et al 2006). Sneller and Laboski (2009) found no difference in corn (Zea mays L.) yield between manure types and synthetic fertilizer.…”

“…Irrigation can increase the potential risk of nitrate N leaching (Power and Schepers 1989), particularly when manure is applied to irrigated land (Chang and Janzen 1996;Davis et al 1997). Tarkalson et al (2006) showed leaching of nitrate from manure and synthetic fertilizer occurred under deficient irrigation, but was 15 to 47% less than under full irrigation. Chang and Janzen (1996) compared excess manure application under rainfed and irrigated conditions in southern Alberta.…”

“…Basso and Ritchie (2005) compared the same amount of total N applied from urea fertilizer, stockpiled manure, and composted manure on a 6-yr corn and alfalfa (Medicago sativa L.) rotation and found that more nitrate N leached from the manure amendment, followed by compost, and then urea. After a 2-yr field study under irrigated corn, Tarkalson et al (2006) found that when cattle manure and ammoniumnitrate fertilizer were applied to meet crop N requirements the amount of nitrate leaching did not differ between the two sources, though the fertilizer tended to leach more. Sexton et al (1996) found that nitrate leached from turkey (Meleagris gallopavo L.) manure was equal to or less than that from urea fertilizer when both sources were applied at equivalent N rates.…”

“…However, the crop data indicated no yield reduction in these amendments. Several studies have compared leaching of N between synthetic and organic sources of N fertilizer (Basso and Ritchie 2005;Tarkalson et al 2006;Olson et al 2009). Basso and Ritchie (2005) compared the same amount of total N applied from urea fertilizer, stockpiled manure, and composted manure on a 6-yr corn and alfalfa (Medicago sativa L.) rotation and found that more nitrate N leached from the manure amendment, followed by compost, and then urea.…”