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
Kimberly A. Moore, Amy L. Shober, Gitta Hasing, Christine Wiese, and Nancy G. West
Joseph R. Heckman, Uta Krogmann, and Christian A. Wyenandt
of shade tree leaves, effect on soil properties and potential uses as an agricultural resource. This review summarizes studies of mulching and amending soils with shade tree leaves and their potential in agricultural production. The review includes
Jongtae Lee, Jinseong Moon, Heedae Kim, Injong Ha, and Sangdae Lee
, nutrient uptake, and soil properties affected by different N, P, and K fertilizer levels in the rice–onion cropping system in which rice straw was annually incorporated into the soil after rice harvest. Materials and Methods Field experiment and treatments
Hong Su, He Zhang, Chaoxia Wang, Jianquan Huang, Jiayin Shang, Na Zhang, Dan Wang, and Kai Li
Influence of compost addition on soil properties, root growth and vine performances of Vitis vinifera cv Cabernet sauvigno n Scientia Hort. 225 88 95 doi: 10.1016/j.scienta.2017.06.052 10.1016/j.scienta.2017.06.052 Griffiths, R.I. Thomson, B.C. James, P
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.
Adam D. Karl, Ian A. Merwin, Michael G. Brown, Rebecca A. Hervieux, and Justine E. Vanden Heuvel
Four under-vine management treatments were established in 2011 in a Vitis vinifera L. ‘Cabernet Franc’ vineyard in the Finger Lakes region of New York: cultivation (CULT), native vegetation (NV), white clover Trifolium repens L. (WC), and glyphosate herbicide (GLY) as the control. Previously installed drainage lysimeters were used to monitor nutrient and pesticide concentrations in leachate water samples. Differences in the physical structure of soils among treatments were only observed in the 4th year of the study when the top 6 cm of CULT soils had greater bulk density than the other treatments, and less porosity and available water capacity than WC soils. WC soils had 17% greater organic matter than CULT soils, and 46% greater aggregate stability than GLY soils. Soil microbial respiration was generally greater in NV and WC treatments than GLY and CULT. Dissolved organic carbon (DOC) leachate concentrations were greater in GLY and CULT compared with NV and WC, having annual mean DOC leachate concentrations as much as 36% greater than the cover crop samples. Mean annual total nitrogen (TN) leachate concentrations of CULT and NV were less than GLY and WC samples by as much as 86%. In 2012, GLY soils leached greater concentrations of imidacloprid insecticide and more imidacloprid metabolites than the other three treatments, with the proportion of samples testing positive for measurable concentrations of imidacloprid or imidacloprid metabolites at least five times greater in GLY than the other treatments. Cumulatively, these factors demonstrate the potential of under-vine cover crops to maintain soil quality and decrease the leaching of nutrients and agrochemicals in vineyards in comparison with conventional practices.
Upendra M. Sainju and Bharat P. Singh
R. M. Davis Jr. and V. H. Schweers
Concentrations of soluble solids (SSC) in fruits of Cucumis melo L., cv. PMR 45, were positively correlated with 2 physical measures of soil samples from producing fields: a) the degree of cracking which occurred during dehydration, and b) the rapidity with which water or a CaSC>4 solution percolated the soils. Very low SSC was associated with sandy, non-cracking soils, which in addition permitted only low rates of percolation. Low SSC also was found to be associated with soils having subsurface hardpans or dense subsoil strata, and also with the distance to lower bounds of plant containers and experimentally placed barriers which obstructed downward root growth. SSC, under adverse conditions, varied further as a function of fruit numbers per plant.
D.S. NeSmith, G. Hoogenboom, and D.V. McCracken
Three summer squash (Cucurbita pepo L.) cultivars were grown using conventional tillage and no-till soil management practices during 1991 and 1992 in the mountain regions of Georgia. Soil bulk density and N content as well as crop dry weight, leaf area, and yield were monitored to assess the potential for using conservation tillage in squash production. Soil bulk density of the surface (0 to 10 cm) layer under no-till exceeded. that under conventional tillage at planting by 0.25 Mg·m-3, and 1 month after planting by as much as 0.16 Mg·m-3. However, growth-limiting bulk densities (>1.45 Mg·m-3) did not occur. Total soil N to a 30-cm depth was similar for the two tillage regimes. There were no significant cultivar × tillage interaction effects on plant dry weight, leaf area, or crop yield. Total yields were similar for the two tillage regimes; however, early yield during 1991 was 27% less using no-till. There is potential for the use of conservation tillage in summer squash production in the southeastern United States. However, the current lack of registered herbicides for weed control and possible early market price incentives are likely disadvantages to widespread acceptance of such cultural practices.