to assess the short-term effects of vermicompost as soil amendments or leachate on soil properties, and spinach growth, physiology, and nutritional value. Materials and Methods Plant materials and treatments. Two trials, each with four replications
Chenping Xu and Beiquan Mou
W.G. Harris, M. Chrysostome, T.A. Obreza, and V.D. Nair
production while minimizing environmental impacts requires an understanding of how soil properties affect the fate of water and nutrients ( Muchovej et al., 2005 ; Simonne and Hochmuth, 2007 ; Stamps, 1996 ; Thompson et al., 2007 ). Soils strongly
Bryant C. Scharenbroch
experiment was conducted to determine the impacts on tree and soil properties of varying rates of ACT. Treatment effects were examined for two tree species ( Acer saccharum and Quercus macrocarpa ) and three soil types (sand, uncompacted loam, and compacted
Mohamed Badrane Erhioui, A. Karam, and S. Yelle
The large amount of organic carbon content present in de-inking residues makes them attractive for use in agricultural soils as an organic soil amendment. Greenhouse bioessays were undertaken to evaluate the agronomic value of de-inking sludge (DS). It was incorporated in a sandy soil to study the effects of different rates of de-inking residue amendments and N fertilizer combinations on soil properties and growth of corn. Particular attention was given to trace element concentrations. In a split factorial design, three variables were investigated: harvest time (after 20, 40, and 60 days), application rates of DS (0, 35, 70, and 105 t·ha–1), and four N rates (0, 140, 280, and 420 kg·ha–1). Chemical analyses of the fresh residues did not indicate the presence of heavy metals at levels potentially toxic to the environment. Soil chemical properties were clearly improved following the incorporation of DS. For example, adding different amounts of DS had a significant impact on the pH, the cation exchange capacity, and soil moisture. In addition, salinity was not affected with DS application. Seed germination was high in all the treatments and was not significantly influenced by DS application. Moreover, results on vegetative growth indicated a good relationship between the C:N ratio and biomass production. The DS combined with supplemental fertilizer seems to have a positive effect on plant growth. Overall, these results suggest that the limiting factor in de-inking paper sludge valorization is the amount of N available to the plant. Also, no other toxic products were found that could be harmful to the environment.
Woo Soo Kim, Hee Jung Kim, and Seong Bong Kim
The energized water, Bio-Green Water (B.G. Water) was manufactured through a series of processes: water purification → adding catalysts → exposure with special energy spectra → filtering, by Kyungwon Enterprise Co. B.G. Water was treated with irrigation of 4 liters/tree at 30 Apr. 1994 and 8 liters/tree at 20 June 1994 in the `Fuji' apple orchard soil, and a pasting to the trunk of apple trees at 20 Apr. 1994. In terms of orchard soil property, Ca and Mg contents were outstandingly increased; however, P2O5 was decreased and K2O was not influenced by irrigation of B.G. Water. The B.G. Water treatment changed soil pH from 4.71 to 5.81 of surface soil level (0 to 20 cm) and from 4.82 to 6.45 of deeper soil level (30 to 50 cm). B.G. Water treatment showed higher soluble solids in apple fruit juice, and lower flesh browning after peeling than that of control. Of mineral contents in fruit skin, Ca was increased; however, N was decreased by the B.G. Water treatment. Of the four solvents fraction for Ca extraction, water-soluble Ca content was increased in the fruit skin treated with B.G. Water, whereas the contents of N, P, Ca, Zn, and B were decreased in the leaves and stem bark of apple trees treated with B.G. Water.
Hyun-Sug Choi, Curt R. Rom, Mengmeng Gu, and Jason McAfee
Seasonal variations of nutrient concentrations in soil and apple leaves, soil properties, weed density, and tree performance were observed for response to four groundcover managements systems: 1) mowed control; 2) plastic woven landscape fabric; 3) wood chip mulch; and 4) shredded commercial paper mulch. Soil sampled below the wood chip and shredded paper mulch treatments had higher NO3-N concentrations during the season. Soil below the shredded paper mulch had greater soil Ca, Na, and Zn than other treatments. Soil sampled below wood chip mulch had higher Mg and B. Leaf K was greater for trees grown with bark chip mulch than the other treatments. Overall, the seasonal patterns of N, P, and K decreased and had similar patterns as previously reported conventionally grown orchards. The leaf Ca and Mg increased during the season for all treatments. The concentration of other microelements had patterns similar among all treatments. Seasonal soil pH decreased during the season and was affected by treatments. During the season, water infiltration was faster into the soil covered with shredded paper mulch. The organic matter was greater in soil under the wood chip mulch at the 15-cm soil depth. Very little weed invasion occurred in the landscape fabric through August. Trees grown with shredded paper and wood chip mulch treatments had greater trunk cross-sectional area compared to trees grown under landscape fabric after 5 years; however, the latter treatment resulted in greater tree height, tree canopy spread, and fruit yield.
Kimberly A. Moore, Amy L. Shober, Gitta Hasing, Christine Wiese, and Nancy G. West
raised-bed plots were 1.22 and 2.69 mg·kg −1 , respectively. In contrast, mean initial soil NO 3 + NO 2 –N and NH 4 –N in the field plots were 3.95 and 1.46 mg·kg −1 , respectively. Table 1. Mean soil properties for initial soil samples collected from
The rate of full hydration for several hydrophilic polymers differed greatly (starch-based polymers > propenoate-propenoamid copolymer > polyacrylamide). Maximum water retention in distilled water varied from over 500 g to 57 g of water per of different dry materials. All polymers retained less water in the presence of metal ions or fertilizers, with substances releasing Fe+2 being the most detrimental. Potting media containing a polyacrylamide polymer reached maximum water retention after 6 irrigations, while those with Micromax (micronutrient source) required 10 irrigations to reach maximum hydration. The water-holding capacities of the media declined after repeated fertilization. Medium bulk density, total watet retention, and water retention per unit volume of medium were increased by the incorporation of the polymer, regardless of the presence of Micromax. Non-capillary porosity in medium amended with Micromax progressively decreased as the amount of the polymer increased, but remained unchanged in medium without Micromax. Repeated wet-dry cycles resulted in decreased water retention and increased non-capillary pore space of the media.