Allen Brett L, Mallarino Antonio P
Dep. of Agronomy, Iowa State University, Ames, IA 50010, USA.
J Environ Qual. 2008 Jan 4;37(1):125-37. doi: 10.2134/jeq2007.0125. Print 2008 Jan-Feb.
Excessive manure phosphorus (P) application increases risk of P loss from fields. This study assessed total runoff P (TPR), bioavailable P (BAP), and dissolved reactive P (DRP) concentrations and loads in surface runoff after liquid swine (Sus scrofa domesticus) manure application with or without incorporation into soil and different timing of rainfall. Four replicated manure P treatments were applied in 2002 and in 2003 to two Iowa soils testing low in P managed with corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotations. Total P applied each time was 0 to 80 kg P ha(-1) at one site and 0 to 108 kg P ha(-1) at the other. Simulated rainfall was applied within 24 h of P application or after 10 to 16 d and 5 to 6 mo. Nonincorporated manure P increased DRP, BAP, and TPR concentrations and loads linearly or exponentially for 24-h and 10- to 16-d runoff events. On average for the 24-h events, DRP, BAP, and TPR concentrations were 5.4, 4.7, and 2.2 times higher, respectively, for nonincorporated manure than for incorporated manure; P loads were 3.8, 7.7, and 3.6 times higher; and DRP and BAP concentrations were 54% of TPR for nonincorporated manure and 22 to 25% for incorporated manure. A 10- to 16-d rainfall delay resulted in DRP, BAP, and TPR concentrations that were 3.1, 2.7, and 1.1 times lower, respectively, than for 24-h events across all nonincorporated P rates, sites, and years, whereas runoff P loads were 3.8, 3.6, and 1.6 times lower, respectively. A 5- to 6-mo simulated rainfall delay reduced runoff P to levels similar to control plots. Incorporating swine manure when the probability of immediate rainfall is high reduces the risk of P loss in surface runoff; however, this benefit sharply decreases with time.
过量施用猪粪磷会增加磷从农田流失的风险。本研究评估了在施用液态猪（Sus scrofa domesticus）粪肥后，无论是否将粪肥混入土壤以及不同降雨时间情况下，地表径流中总径流磷（TPR）、生物可利用磷（BAP）和溶解性反应磷（DRP）的浓度及负荷。2002年和2003年，对两种磷含量低的爱荷华州土壤进行了4次重复的猪粪磷处理，土壤采用玉米（Zea mays L.）-大豆[Glycine max (L.) Merr.]轮作管理。每次施磷量在一个地点为0至80 kg P ha(-1)，在另一个地点为0至108 kg P ha(-1)。在施磷后24小时内、10至16天以及5至6个月后进行模拟降雨。对于24小时和10至16天的径流事件，未混入土壤的猪粪磷使DRP、BAP和TPR的浓度及负荷呈线性或指数增加。对于24小时事件，平均而言，未混入土壤的猪粪中DRP、BAP和TPR的浓度分别比混入土壤的猪粪高5.4倍、4.7倍和2.2倍；磷负荷分别高3.8倍、7.7倍和3.6倍；未混入土壤的猪粪中DRP和BAP浓度分别占TPR的54%，混入土壤的猪粪中占22%至25%。在所有未混入土壤的磷施用量、地点和年份中，降雨延迟10至16天导致DRP、BAP和TPR的浓度分别比24小时事件低3.1倍、2.7倍和1.1倍，而径流磷负荷分别低3.8倍、3.6倍和1.6倍。模拟降雨延迟5至6个月可使径流磷降低至与对照地块相似的水平。在近期降雨可能性高时混入猪粪可降低地表径流中磷流失的风险；然而，这种益处会随着时间急剧下降。
