Soybean Yield and Heterodera glycines Responses to Liquid Swine Manure in Nematode Suppressive Soil and Conducive Soil

摘要

The soybean cyst nematode (SCN), Heterodera glycines, is a major factor limiting soybean yield. Experiments were conducted in 2009 and 2010 to determine the effects of liquid swine manure and chemical fertilizer PK on soybean and corn yields, and on SCN population in an SCN-suppressive ?eld (S-Site) and an SCN-conducive ?eld (C-Site) in Minnesota. The experiment was a split-plot design with crop sequences as main plots and fertilizer treatments as subplots. The 2-yr crop sequences were Sus-Sus, ResSus, and Corn-Sus, where Sus was SCN-susceptible soybean, and Res was SCN-resistant soybean. The fertilizer treatments were manure, PK, and a nonfertilizer as control. Manure did not reduce SCN egg population density but resulted in 31% lower SCN second-stagejuvenile(J2) populationdensityattheS-Siteat 45d afterplanting(DAP)in 2009.Manurealsoreducedspiralnematode (Helicotylenchus spp.) population densityby52% compared with PK and nonfertilizer treatmentsat S-Siteat 45 DAP in 2009. The crop sequence of Corn-Sus and Res-Sus reduced the SCN egg and J2 but increased spiral nematode population density at both sites. An increase of 1.4 Mg/ha and 0.5 Mg/ha in yield of susceptible soybean was observed in manure and PK treatments, respectively, at the C-Sitein 2009. Corn yield was2.8 Mg/haand 5.0 Mg/ha greater when treated with manurethan nonfertilizer at the S-Site and C-Site, respectively. This study suggests that soil fertility management may be a useful strategy to alleviate the SCN damage to soybean.