Soil Water Leaching Research Articles

Precipitation and irrigation dominate soil water leaching in cropland in Northern China

Studying the effects of precipitation and irrigation on soil water leaching are critical for maintaining agricultural environment in Northern China, where uneven irrigation has been applied coupled with a broad spectrum of climatic conditions. We conducted consecutive a 4-year field experiment from 2008 to 2011 with lysimeters buried 90 cm deep to determine soil water leaching. Results indicated that amounts of soil water leaching in greenhouse croplands were significantly higher than that in open field croplands. Rainy season is the key period for soil water leaching in semi-humid areas in open fields, accounting for 88.6% of the annual amount of leachate, while excess irrigation was a significant factor for soil water leaching in semi-arid areas. Irrigation pattern affects soil water leaching by determining irrigation volume. There was significant leaching with border irrigation, particularly in the Winter-Spring seasons (from Jan. to Jun.), while drip irrigation led to a 62–74% reduction of irrigation water with no leaching happened. With water-saving irrigation, the effects of fertilization on nitrogen leaching were not significant.

Fertilization Methods Affect Growth, Color and Nitrogen Leaching of Winter Annuals in Landscape Beds

Abstract Two experiments were conducted to evaluate fertilizer formulations, methods of application, and frequency of application on growth of winter-grown landscape bedding plants and N leaching. In Expt. 1, ‘Majestic Giants White’ pansy (Viola xwittrockiana Gams.) and ‘Telstar Purple’ dianthus (Dianthus chinensis L.) were planted in raised beds. Four inorganic fertilizer formulations were applied at 4.9 g/m2 N (1 lb N/1000 ft2) either incorporated pre-plant or topdressed post-plant. Additional treatments included an industry practice (IP) of incorporating a granular water soluble (GWS) fertilizer pre-plant and topdressing a controlled release fertilizer (CRF) post-plant, and a pre-plant incorporation of an organically-based fertilizer (OBF) composed of recycled newspaper amended with chicken manure. In Expt. 2, similar treatments were applied to the following species: ‘Bingo Blue with Blotch’ pansy, ‘Telstar Crimson Picotee’ dianthus, and ‘Tall Red’ snapdragon (Antirrhinum majus L.). Across both studies, CRFs generally improved foliar color and plant size compared to GWS fertilizers, while reducing total-N in soil-water in some instances. The IP treatment provided superior foliar color and larger plants compared to other inorganically fertilized plants, while causing no more or less total-N in soil-water leaching below plant roots. Response to the OBF differed among the two experiments. The OBF resulted in adequate foliar color and plant size and reduced total-N recovered from soil-water in Expt. 1. However, it generally provided superior foliar color and size compared to all other treatments in Expt. 2, but also caused elevated levels of total-N in soil-water.

Seasonal Change of Soilwater and Streamwater Chemistries in the Tsukuba Experimental Forested Basin

The soilwater and streamwater chemistries in the Tsukuba experimental forest were examined using data sets gained during four years since 1985. The concentrations of nitrate nitrogen and potassium etc., the major essential elements for forest plant growth, rose in surface soilwater in summer season due to decomposing organic substances accumulated in surface soil. Furthermore, the soilwater leaching during successive storm events increased those concentrations in streamwater through summer season. Such coincidence of the time-varied pattern between solute concentration and flowrate brought in the rise of the annual streamsolute concentration like nitrate nitrogen and potassium with increasing the annual streamwater amount.

EFFECT OF ELEMENT CYCLE ON STREAMWATER CHEMISTRY IN FORESTED BASIN

Two types of the chemical changes of streamwater during storm runoff were found: Type I which recovers approximately the same concentration in the recession limb as the baseflow level prior to the runoff event; Type II which overshoots the baseflow level. Main solute belonging to Type I is SiO2, and that to Type II is NO3--N.To relate the element cycle in forest ecosystem to the streamwater chemistry, element content in forest soil was analyzed. This proves that silicon content in forest surface soil is somewhat lower than in deeper soil, while nitrogen becomes greatly enriched in surface soil. Besides, the difference between element contents in soil makes a change of vertical soilwater chemistry in SiO2 and NO3--N concentrations, and consequently generates the chemical changes of streamwater through soilwater leaching.

Elemental Abundances in Appalachian Fly Ash

Seven samples of fly ash and four of spoil area material from the Appalachia coal regions were analyzed by neutron activation (NAA) for elemental abundances. Gross concentrations of Na, Al, Fe, V, and Ti detected appear to corroborate other analytical techniques. Detection of concentrations less than 2000 ppm were obtained for Mn, Co, Sc, Th, U, Tb, Tm and La. Selective separation appears to be occurring in the generation of fly ash and stack gasses for Sc/Fe and Sc/Co ratios normally anticipated in crushed coal. The diversity of trace elements which may be involved in leaching processes and subsequent environmental hazards are not well known nor established at this time. Trans. Kans. Acad. Sci., 76 (1), 1973. Introduction Fly ash residues from coal-fired electrical generating plants have been proposed as soil modifiers to neutralize coal strip mine spoil areas in grassland reclamation projects throughout the United States. Fly ash tends to concentrate the trace elements inherent in the original coal beds from which this by-product is produced. A paucity of data exists in studies of the micro-constituents which may be present in beneficial or harmful concentrations to substantially affect the physiology of plants and animals within the food subchain created by fly ash-soil modifications. The intent of these studies was to formulate a procedure to identify the nature and concentration of some of these trace elements by neutron activation analysis. Capp and Spencer (1970) considered ten macro/semimicro constituents found in ash as they affect pedology and agronomy. Of the 17 most commonly occurring elements' in fly ash, boron was noted as the principal offender in restricting growth, followed quickly by aluminum and manganese. Duel et al., (1956) reported standard sensitivities of trace elements in mid-continent coals by the semi-quantitative spectrographic method. With the (NAA) method, it is possible to determine more precise concentrations of the microconstituents and their corresponding synergetic or antagonistic relationships when released directly to the atmosphere or by soil water leaching. Pfitzer, Schroeder and others (1971) argue that these unknown trace elements pose an unseen pollution threat in being recycled and dispersed to the environment. Transactions of the Kansas Academy of Science, Vol. 76, No. 1, 1973. Published January 22, 1974. 1 Department of Geology, Wichita State University. 2 Nuclear Engineering Department, Kansas State University [74] This content downloaded from 207.46.13.180 on Thu, 08 Sep 2016 05:05:15 UTC All use subject to http://about.jstor.org/terms