Studies On Appropirate Physical And Chemical Properties Of Substartes And Composition Of Functional Media For Seedling Production Of Cucumber

Intensive seedling production of vegetable represented by plug seedling gradually wasmoving towards the scale, standardization and modernization. Substrate was the basiccondition of plug seedling, affecting directly the seedling quality. The studies about seedlingsubstrate were concentrated in formula selection, but the studies on suitable physical andchemical was less. Moreover, the volume of seedling plug was limited, and the ability ofwater and nutrient conservation was poor, watered more times, process was cumbersome, theloss of water and nutrient was serious. The paper studies the appropriate physical andchemical properties of substrates and formula of functional media for seedling production ofcucumber and the function of super absorbent polymer and chitosan and controlled releasecompound fertilizer on substrate. The main results as follow:1. The application effects of different proportion of peat，vermiculite and perlite matrixon cucumber seedlings using mixing test design were studied. The results showed that whenthe substrate ratio was peat: vermiculite: perlite=5:2:3（V:V:V），the dry matter weight andseedling index of cucumber seedling were the largest. The contour map was drawn in theobservations of seedling index，under the95%confidence interval of the substrate suitableratio （volume ratio） for peat34⁴5%and vermiculite20³1%and perlite35⁴3%. Throughthe establishment of various physical and chemical properties of peat and vermiculite andpearlite proportion regression model，the cucumber seedling substrate suitable physical andchemical indicators calculated by LINGO11.0,available nitrogen399.0⁵13.5mg.kg-1，available potassium329.0³97.5mg.kg-1，available phosphorus26.4³0.1mg.kg-1，bulkdensity0.17⁰.22g.cm-3，total porosity85⁹0%，EC0.315⁰.425ms cm-1，pH6.8⁷.2，totalorganic carbon29.5³6.3%.2. The mushroom residue compost, peat and vermiculite and perlite were used tocomposite different complex media for cucumber seedling test, with different dosage ofcontrolled release compound fertilizer. The results showed it could meet the need of nutrientof cucumber seedling without nutrient solution with the amount of controlled release fertilizer（N-P2O5-K2O=14-14-14） was1.71².14g L^-1using peat+mushroom residue+vermiculite+ perlite=2:3:2:3（V:V:V:V）.3. In peat+mushroom residue+vermiculite+perlite （2:3:2:3, V:V:V:V） compositesubstrate for the seedling substrate, super absorbent polymers was studied in cucumber holeplate seedling effect. Results show that adding a certain amount of water retention agent caneffectively improve substrate water retention ability and fat accumulation, promote cucumberseedling growth, increase seedling physiological activity and is beneficial to drymatteraccumulation, reduce watering frequency; With the increase of dosage of super absorbentpolymers, the cucumber seedling growth and physiological indexes showed a trend of fallingafter rising first, Comprehensive growth physiological index, under the condition of thisexperiment, the best dosage of super absorbent polymers was4g.L^-1.4. The study evaluated the effects of application amount of chitosan on cucumber plugseedling using peat+mushroom residue+vermiculite+perlite （2:3:2:3，V:V:V:V） as thesubstrate. The results showed that the growth and physiological indicators of cucumber had atrend of rise before lowering; when the application amount of chitosan was4g.L^-1, theemergence rate and stem thick and the seedling index of cucumber was the biggest thanothers,the dry weight increased about42%to the control. Chlorophyll content in leaf andphotosynthetic rate and root activity and root absorption area were higher than others, thecontents of soluble sugar and proline content were highest.5. Using peat+mushroom residue+vermiculite+perlite （2:3:2:3, V:V:V:V） compositesubstrate for the seedling substrate, the coupling effect about super absorbent polymers,controlled release fertilizer and chitosan were studied. The results showed that the superabsorbent polymers, controlled release fertilizer, there was interaction between chitosan andthree coupled effectively improve the physiological activity of cucumber seedlings andresistance, the three factors the best dosage through computer simulation test modeloptimization, get the test under the condition of the three factors of cucumber seedlingsubstrate the best dosage of coupling:super absorbent polymers was3.98⁵.79g·L^-1;controlled release fertilizer was2.17².97g·L^-1, chitosan was4.82⁵.35g·L^-1.