Fallow Versus Wheat Cropping of Unamendedand Manure-Amended Soils Related to Mycorrhizal Colonization, Yield, and Plant Nutrition of Dry Bean and Sweet Corn

Abstract

Previous studies reported manure application to eroded Portneuf silt loam soil (Coarse-silty, mixed, superactive, Durinodic Xeric Haplocalcid) improved dry bean (Phaseolus vulgaris L., cv. Viva) yield to levels of topsoil. These yield increases only correlated with whole-plant zinc (Zn) concentration and soil organic matter. This might be related to enhanced arbuscular mycorrhizal (AM) colonization stimulated by manure application. A greenhouse study with dry bean suggested a relationship between manure application, increased AM colonization, and whole-plant Zn uptake, while ®eld studies with wheat (Triticum aestivum L.) and sweet corn (Zea mays L.) did not. To clarify the apparent contradiction of manure application on AM relationships, the JOURNAL OF PLANT NUTRITION, 24(6), 921±943 (2001) present ®eld study with dry bean and sweet corn was conducted in subsoils on the same experimental site established in 1991 and used in previous studies. The existing rotation also allowed the study of the effects of previously fallowed versus wheat cropped subsoils on yield, AM colonization and nutrition of dry bean and sweet corn. Average mycorrhizal root colonization in dry bean was greater on unamended than on manure-amended soils but was not related to increases in yield, Zn concentration, or Zn uptake. Average colonization of sweet corn roots was generally greater in unamended than manure-amended soils, but yields were greater in manure-amended soils. Colonization of sweet corn roots measured over time was consistently greater in subsoils previously cropped to wheat than fallowed, but yields were similar. Previous wheat-cropping resulted in leveling off of colonization beginning 7 July (second sampling) in dry bean, while previous fallow resulted in continuously increasing colonization throughout the ®ve sampling periods. Bean yields were greater on subsoils previously cropped than fallowed; thus yields were generally not related to AM colonization. Results of our study con®rm other ®eld results where AM colonization was greater in unamended than manure-amended soils and in cropped than in fallowed soils. Any yield increases observed were not closely related to AM colonization.

Precision Placement of Separated Dairy Sludge Improves Early Phosphorus Nutrition and Growth in Corn (Zea mays L.)

“…Similarly, Ryan and Angus (2003) reported that AM colonization was decreased by growing corn after canola, a nonhost crop, or through maintenance of bare fallow with herbicides or tillage. The reduced AM colonization rate can be attributed to the reduction of AM hyphal propagules in the previously fallow soils (Allen et al, 2001; Kabir et al, 1999; Thompson, 1987), slowing the early season colonization.…”

One‐Time Tillage of No‐Till: Effects on Nutrients, Mycorrhizae, and Phosphorus Uptake

“…The benefit of organic amendments on AM fungi has been attributed to increased porosity, enlarged mean weight diameter of aggregates, improved water retention capacity, greater activity of beneficial soil microbes, increased crop rooting, and a better distribution of nutrients in the soil profile (Celik et al, 2004). However, Ellis et al (1992) and Allen et al (2001) found that AM colonization was inconsistently affected by manure applications.…”

Agronomic Management of Indigenous Mycorrhizas

“…Colonization of roots followed the same pattern as the growth of AM fungi hyphae. In contrast, Allen et al (2001) reported a greater AM colonisation of dry bean and sweet corn in unamended than in manured soils.…”