Experimental Study Of The Effect Of Organic Fertilizer On Soil Water Movement

Using soil with improper ways and putting too much chemical material lead tothe decline of soil quantity and Adverse environmental effects, which is not conduciveto agricultural production and vegetative growth. In order to solve this problem, someresearches had been done to improve the soil, among which applicant of organicfertilizer is a common way. Organic matter could increase soil fertility, improve soilstructure, increase silt content, decrease soil bulk density. The objective of our studyis to investigate the influence of organic matter on soil water infiltration and soilsaturated hydraulic conductivity (KS) for Sand soil and Lou soil.The content of organic fertilizer in the soil was set as0%,5%,10%,15%,20%,25%and30%. Three levels were designed for bulk density (depending on trial ofpacking). Soil columns (30cm) with constant head of water were used. Using topwater input method and bottom water input method respectively infiltrated soilcolumn, to determine changes of cumulative infiltration and wetting front depth overtime for both soils. Under the same condition, soil hydraulic conductivity (K) wasdetermined.Conclusions are as follows:1) The addition of organic fertilizer significantly extend the time of completingthe infiltration. Infiltration completing time of Sand soil and Lou soil was extendedwith the increase of organic fertilizer content. At the same time the cumulativeinfiltration is reduced with the increase of the organic fertilizer content. Soil wettingfront depth decreases with the increase of organic fertilizer content. Under top waterinput method when infiltration finished, the difference of cumulative infiltration ofSand soil was not significant. While under top water input method when infiltrationfinished, cumulative infiltration of Sand soil decreased with the increase of organicfertilizer. Under both water input methods when infiltration finished, cumulative infiltration of Lou soil for every organic fertilizer content treatment was notsignificant different.2) The time of completing infiltration extended with the increase of bulk densityfor every treatment of each organic fertilizer content treatment.3) Under different content of organic fertilizer, different bulk density anddifferent water input method, cumulative infiltration and wetting front depth fitted byKostiakov formulas and power function respectively. Every treatment was fitted well.4) KSdecreased with the increase of organic matter content. Under bothwater-input methods, KSof Sand soil linearly declined with the increase of organicmatter. While KSof Lou soil decreased slowly with the increase of organic matter. Thecurve of KSof Lou soil over time fit logarithmic well, because the effect of organicmatter on Lou soil is more complicated the Sand soil.5) As bulk density would decrease when add organic matter to soil, KSwill notsignificantly decrease with the increase of organic matter content for both soils underlower bulk density condition.6) The time when water dropped from soil columns of both Sand soil and Lousoil became longer with adding organic fertilizer. Also the procedure of determinationbecame longer. K decreased with the increase of organic fertilizer content during thewhole determination (except Lou soil of organic fertilizer0%). Under top water input,K of Sand soil changed over time with obvious increase processes or reductionprocesses. While under bottom water input, the changes of K of Sand soil was stable.The curve of K of Lou soil with no organic fertilizer over time would significantchange when adding organic fertilizer. This change of Lou soil was for both waterinput method.7) Under same organic fertilizer content, the time when water dropped from soilcolumns of both Sand soil and Lou soil became longer with the increase of soil bulkdensity. The procedure of determination became longer. K decreased with the increaseof soil bulk density during the whole determination. Under lower bulk density K ofSand soil changed over time with obvious increase processes or reduction processes.Under higher bulk density the changes of K was stable.