Author
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Ritchey, Kenneth |
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SCHUMANN, CAROL - FORMER USDA-ARS SCIENTIST |
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Submitted to: HortScience
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/20/2004 Publication Date: 12/27/2004 Citation: Ritchey, K.D., Schumann, C.M. 2005. Response of woods-planted ramps (wild leeks) to surface-applied lime or gypsum. Hortscience. v. 40. p. 1516-1520. Interpretive Summary: Concern about over-harvesting of wild ramps (Allium tricoccum Ait.) has led to interest in commercially growing the crop instead of relying on existing populations. There is little published information about effects of soil preparation, plant spacing, and type of planting material on survival and growth of ramps. Ramps usually are found growing in moist wooded sites on soils with relatively high pH and nutrient levels, but because such sites are scarce, we wanted to see if ramps would respond to application of Ca amendments in a droughty, acidic site. We planted in early March, using single bulbs, two bulbs joined together, or bulbs obtained by breaking joined bulbs apart, and two plant spacings. Immediately after planting we surface-applied 3000 lb/ac slaked lime (Ca(OH)2) to supply Ca and increase soil pH near the surface, or 6900 lb/acre gypsum (CaSO4 .2H20), to rapidly increase soil Ca levels throughout the profile without affecting pH. Half of the plants were harvested 2 years after planting and the other half 3 years after planting. In the 2-year harvest, both amendments increased plant survival and per-plant weight, indicating that increasing the amount of Ca available was important to ramps. For the 3-year harvest, ramps in the slaked lime treatment were heavier than in the gypsum treatment indicating that slaked lime was probably the better Ca source. Single or joined bulbs survived better than bulbs obtained by breaking joined bulbs in two. Plants spaced at 12-by-12 inches survived better than plants in the 6-by-6 inch spacing. While more research is needed to overcome all limitations to commercial planting of ramps in acidic droughty sites, our data show that Ca application is very beneficial to growth and survival of ramps. Technical Abstract: Ramps (Allium tricoccum, Ait.), also known as wild leeks, are increasingly sought after and gathered from the wild. As a result, native populations are over-harvested. Forest sites with high soil Ca are scarce and little is known about potential benefits of ameliorating dystrophic soils with Ca for improving survival and growth of planted ramps. We surface-applied 3316 kg/ha slaked lime and 7704 kg/ha gypsum as Ca sources and harvested ramps 2 and 3 years after planting of bulbs. The experiment was located in southern West Virginia in a west-facing oak (Quercus spp.) and pine (Pinus alba) woodlot from which pine had been removed. The soil was mapped as a Rayne silt loam (fine-loamy, mixed, mesic Typic Hapludult). Approximately 36 months after application, slaked lime had increased Ca levels in this acidic, nutrient-poor site as deep as the 22.5- to 30-cm layer, and increased pH in the 2.5- to 5-cm layer from 3.96 to 4.67. Gypsum application raised Ca concentration in the 22.5- to 30-cm layer from 0.2 to 0.7 cmolc/kg, but had little effect on pH anywhere in the profile. Effects of amendments on Al, Mn and Mg were generally limited to the O1, O2, and 0- to 2.5-cm layers. After 3 years of growth, survival rate was 0.24 in the control treatment and 0.70 in the Ca-amended treatments. Compared to the control, per-plant weight after 2 years of growth was increased an average of 59% by the Ca treatments. After 3 years of growth per-plant weight was doubled by the slaked lime application, but benefits of gypsum application were less marked than they were after 2 years of growth. Planting bulbs obtained by splitting joined bulbs into two reduced plant survival compared to planting joined or single bulbs. Mean survival of ramps in a 30 cm x 30 cm spacing after 3 years growth was 0.61 vs. 0.48 in a 15 cm x 15 cm spacing. |
