Effects Of Active Carbon Application On Soil Charachteristics And Growth Of Spring Maize

This paper mainly studied the effects of application of active carbon on soil physicalproperties as bulk density, porosity and etc., soil water characteristics as infiltration,evaporation, water holding capacity and etc., soil nutrient leaching and profile distribution byindoor soil column simulation tests. It also studied the effects of active carbon application onspring maize growth and nutrient absorbing by pot culture, aiming at exploring soil improvingability of active carbon as soil amendment, and providing a theoretical basis for its applicationin moisture and fertilizer conservation of farmland in arid areas.The main conclusions are asfollows:(1) The application of active carbon into soil can decrease soil bulk density over control.Less decreased within short period, while as time went on,the decreasing degree increasedsignificantly.High-amount application had a significant effect on soil bulk decreasing densityover long period with relatively obvious improving effect on soil porosity.(2) Low-amount of active carbon application can increase soil infiltration capacity to acertain degree with the best improving effect at0.3%mass fraction. Soil accumulatingevaporation decreased with the increase in active carbon application amount, high-amountapplication has a relatively obvious effect on soil evaporation inhibition. Under the conditionof unincubation, the active carbon applications can all increase soil water holdingcapacity.After natural incubation for30d, different treatments had almost the same soil waterholding capacity. At the low-suction section treatment of0.1%presented better water holdingcapacity,0.9%at medium-suction section.(3) Active carbon application can to a certain degree inhibited the leaching of nitratenitrogen and organic carbon with water into deeper soil layers, basically with a increasingtrend in inhibiting effect with the increase in use dosage. Low-amount active carbon treatmentexhibited stronger retaining and absorbing effect on soil alkali-hydrolyzable nitrogen at topsoil over higher amount.(4) At the seedling stage of maize, active carbon treatment inhibited the growth of plantheight and leaf area and dry matter accumulation. As time went on, the later growth rate underactive carbon treatment were faster than control, with gradually decreasing difference from control, and all passing control at the end of jointing stage.Active carbon treatments of massfraction of0.6%and0.9%had a better effect on increasing aboveground dry weight at matureperiod.And the treatment of0.6%had a significant effect on increasing seed weight andaboveground dry weight over other treatments. Chlorophyll content was always the highestunder treatment of0.9%at seedling and jointing stages; the addition of relatively higheramount of active carbon into soil（mass fraction of0.6%and0.9%）both had significantlyhigher net photosynthetic rate and transpiration rate than control.(5) Treatments of high-amount active carbon （mass fraction0.6%and0.9%）had highertotal content of nitrogen in aerial parts and total nitrogen mass fraction in subterranean partsthan control，with significant difference in total nitrogen mass fraction in subterranean partsfrom;total contents of nitrogen in milpa under different treatments were all higher thancontrol with exception of the treatment of0.3%mass fraction, and treatments of active carbonall had higher total nitrogen mass fraction residual in soil than control, presenting better effecton soil nutrient adsorption and utilization.