Soluble nitrogen (ammonium and nitrate) is released when soil organic matter is mineralized. The amount of N released by this process depends on the amount of organic matter present and soil temperature. Cranberry (Vaccinium macrocarpon Ait.) grows in acidic soils with a wide range in organic matter content. To evaluate how soil N release is affected by soil temperature, intact soil cores were collected from sites that had received no fertilizer and placed in PVC columns. Four different soil types, representing the range of cranberry soils (sand, sanded organic soil, peat, and muck), were used. Each column was incubated sequentially at six different temperatures from 10 to 24 °C (2.8 °C temperature intervals) for 3 weeks at each temperature, with the soils leached twice weekly to determine the amount of N release. The total amount of N in leachate was highest in organic soils, intermediate in the sanded organic soil, and lowest in the sands. The degree of decomposition in the organic soils was important in determining which form of N predominated. In the more highly decomposed organic soil (muck), most of the N was converted to nitrate. The data from this study resulted in the development of two models—one predicting the N mineralization and the other predicting the proportion of N in each of the two forms. Key factors for N release rate were soil temperature, percentage of clay, and organic carbon content. For predicting the proportion of N as ammonium vs. nitrate, key factors were soil temperature, soil pH, and the distribution of mineral matter in the silt and sand fractions.
tillage or herbicides. Although effective, herbicides and excessive tillage lead to environmental issues such as herbicide-resistant weeds ( Chatham et al., 2015 ) and reduced soil organic matter ( Reicosky et al., 1995 ). Cover crops are an alternative to
successful: 1) planting in pine bark beds ≈6 to 8 inches deep with overhead irrigation, 2) planting in high organic matter (greater than 3%) spodic-type or allied sand soil series, and 3) planting in sand or loamy sand soils and amending the soil with pine
Abstract
Lettuce plants (Lactuca sativa L. ‘Black Seeded Simpson’) were grown under greenhouse conditions in soils artificially contaminated with PbCl2. The addition of organic matter or P substantially reduced Pb uptake. Different types of organic matter reduced uptake in the following way, from most to least effective, respectively: muck soil > manure > ground-up leaves > sphagnum peat. The addition of 100 ppm or greater P also reduced Pb uptake. Lead deposited onto leaves from the emissions of a gasoline engine could be removed by washing leaves in 1% aqueous acetic acid or 0.5% liquid detergent solution.
.) activity and reduce photosynthetic capacity of plants ( Barney et al., 2007 ; Golchin et al., 1995 ; Jackson et al., 2003 ; Magdoff and van Es, 2009 ; Tanigoshi et al., 2003 ). The highest percentage of soil organic matter is present on or near the soil
for establishment of both conventional and organic northern highbush blueberry ( Vaccinium corymbosum L.), including incorporating or amending with organic matter before planting, mulching, and fertilization ( Bañados et al., 2012 ; Cox, 2009; Krewer
Native nitrogen is released when soils are mineralized. The amount of N released by this process depends on the amount of organic matter present and soil temperature. Cranberry (Vaccinium macrocarpon Ait.) grows in acidic soils with a wide range in organic matter content. To evaluate release of cranberry soil N at varied soil temperatures, intact soils were collected from sites that had received no fertilizer. Soils were cored and placed in polyvinyl chloride (PVC) columns 20 cm deep × 5 cm in diameter. Four different soil types, representing the array of conditions in cranberry soil (mineral, sanded organic, organic peat, and muck) were used. Additional columns of sand soil (pH 4.5) that had been pH adjusted to high (6.5) and low (3.0) were also prepared. Each column was incubated sequentially at six different temperatures from 10 to 24 °C (2.8 °C temperature intervals) for 3 weeks at each temperature, with the soils leached twice weekly to determine the amount of N release. The total amount of N in leachate was highest in the organic soils, intermediate in the sanded organic, and lowest in the sands. At the lowest temperature (10 °C), higher amounts of N were released in sanded organic and sand than in organic soils. This was attributed to a flush of mineralization with change in the aerobic status and initial soil warming. The degree of decomposition in the organic soils was important in determining which form of N predominated in the leachate. In the more highly decomposed soil (muck), most of the N was converted to nitrate. In the pH adjusted sand, high soil pH (6.5) resulted in an increase in nitrate in the leachate but no change in ammonium when compared to non-adjusted (pH 4.5) and acidified (pH 3.0) treatments. This study suggests that for cranberry soils with organic matter content of at least 1.5% little to no soil-applied fertilizer N is needed early in the season, until soil temperatures reach 13 °C. This temperature is consistent with the beginning of active nutrient uptake by roots. Soil N release from native organic matter was fairly consistent until soil temperatures exceeded 21 °C, indicating that when temperatures exceed 21 °C, planned fertilizer applications should be reduced, particularly in highly organic soils.
Abstract
Plants are exposed to many nutritional problems in the environment. The interaction of soil pH, mineral reserves, moisture content, and organic matter content are just a few of the factors influencing the availability of nutrients and the type of mineral stress affecting a plant (48).
leaching or denitrification, different application strategies, or different levels of net mineralization of N in native soil organic matter. Growth-limiting factors other than N may also explain the absence of a yield increase, like in two of the cited
plasma atomic emission spectrophotometry [ICP-AES (Spectro; Ametek Materials Analysis Division, Kleve, Germany)], organic matter content from loss on ignition, and wet aggregate stability according to the Cornell Soil Health Test ( Gugino et al., 2009