| In order to develop labor-saving soil management mode, using the field test method,the effects of mulching with different materials (dairy manure, wood chips, alfalfa) on soilphysical and chemical properties, growth of grass, number of soil microorganisms, numberof roots, photosynthetic characteristics of walnut tree, walnut yield and nut quality werestudied from2011to2012, the results were as follows:1. In the dry season in June20th2011, the soil water contents in soil layer of0-20cmwith mulching dairy manure, wood chips, alfalfa and control (non-mulching) were16.99%,15.59%,14.62%and14.05%; soil water contents in soil layer of20-40cm were13.62%,12.68%,11.57%and11.07%; in the two soil layers, soil water contents of mulching dairymanure were significantly higher than those of mulching wood chips and alfalfa, mulchingwood chips were significantly higher than those of mulching alfalfa, which were allsignificantly higher than those of control (non-mulching). Soil water contents in soil layerof40-60cm had no significant differences between mulching treatments and control.2. After two years mulching dairy manure, the soil bulk densities in soil layers of0-20cm,20-40cm,40-60cm were1.24g/cm3,1.32g/cm3,1.43g/cm3, which decreased by9.9%,7.7%,5.3%respectively compared with before mulching, and they were the largestdecline in all treatments; the soil bulk densities in the3soil layers with mulching woodchips were1.33g/cm3,1.37g/cm3,1.45g/cm3, which decreased by5.7%,4.2%,3.9%; thesoil bulk densities in the3soil layers with mulching alfalfa were1.39g/cm3,1.41g/cm3,1.49g/cm3,which decreased by1.4%,1.4%,1.3%.3. After two years mulching dairy manure, the capillary porosities in soil layers of0-20cm,20-40cm,40-60cm were36.67%,34.19%,32.80%, which were the largest in alltreatments; those of mulching wood chips were3.29%,33.90%,32.24%；those ofmulching alfalfa were32.03%,32.70%,32.25%; and the capillary porosities of all themulching treatments were significantly higher than those of control (non-mulching).4. After two years mulching, the soil organic matter contents in soil layer of0-20cmwith mulching dairy manure, wood chips, alfalfa and control (non-mulching) were13.332mg/g,9.794mg/g,9.331mg/g,4.067mg/g; the total nitrogen contents were1.119mg/g,0.863mg/g,1.190mg/g,0.501mg/g; the total phosphorus contents were1.077mg/g, 0.881mg/g,0.856mg/g,0.584mg/g; the total potassium contents were8.624mg/g,7.884mg/g,7.803mg/g,7.159mg/g; mulching dairy manure treatment in other items weresignificantly higher than those of other treatments and control (non-mulching) except thesoil total nitrogen content was significantly lower than those of mulching alfalfa.The soil organic matter contents in soil layer of20-40cm with mulching dairy manure,wood chips, alfalfa and control (non-mulching) were11.575mg/g,8.942mg/g,8.553mg/g,7.228mg/g; the total nitrogen contents were0.994mg/g,0.782mg/g,0.834mg/g,0.727mg/g; the total phosphorus contents were0.889mg/g,0.757mg/g,0.702mg/g,0.765mg/g;the total potassium contents were9.084mg/g,8.197mg/g,8.167mg/g,7.332mg/g; all theitems of mulching dairy manure were significantly higher than other treatments and control(non-mulching).The soil organic matter contents in soil layer of40-60cm with mulching dairy manure,wood chips, alfalfa and control (non-mulching) were6.780mg/g,5.748mg/g,5.545mg/g,8.399mg/g; the total nitrogen contents were0.744mg/g,0.643mg/g,0.719mg/g,0.918mg/g; the total phosphorus contents were0.701mg/g,0.665mg/g,0.635mg/g,0.986mg/g;the total potassium contents were9.300mg/g,8.399mg/g,8.387mg/g,7.505mg/g.5. In the dry season in June20th2012, the walnut transpiration rates of mulchingdairy manure, wood chips, alfalfa and control were3.25mmol·m-2·s-1,3.45mmol·m-2·s-1,3.60mmol·m-2·s-1,3.97mmol·m-2·s-1; WUE were1.31μmolCO2·mmol-2H2O,1.02μmolCO2·mmol-2H2O,0.91μmolCO2·mmol-2H2O,0.74μmolCO2·mmol-2H2O.6. After two years mulching, the numbers of bacteria in soil layers of0-20cm,20-40cm,40-60cm with mulching dairy manure were6.82×106cfu/g,3.14×106cfu/g,2.12×106cfu/g; the numbers of fungi in soil layers of0-20cm,20-40cm,40-60cm with mulchingdairy manure were2.35×105cfu/g,1.18×105cfu/g,1.18×105cfu/g；the numbers ofactinomyces in soil layers of0-20cm,20-40cm,40-60cm with mulching dairy manurewere5.06×104cfu/g,3.29×104cfu/g,2.12×104cfu/g.The numbers of bacteria in soil layers of0-20cm,20-40cm,40-60cm with mulchingwood chips were2.82×106cfu/g,2.12×106cfu/g,0.94×106cfu/g; the numbers of fungiwere1.18×105cfu/g,0.94×105cfu/g,0.94×105cfu/g; the numbers of actinomyces were3.41×104cfu/g,2.70×104cfu/g,1.64×104cfu/g.The numbers of bacteria in soil layers of0-20cm,20-40cm,40-60cm with mulchingalfalfa were2.12×106cfu/g,2.12×106cfu/g,0.82×106cfu/g; the numbers of fungi were1.41×105cfu/g,1.18×105cfu/g,1.18×105cfu/g; the numbers of actinomyces were2.82×104cfu/g,2.59×104cfu/g,1.29×104cfu/g. The numbers of soil microorganisms of allmulching treatments were significantly higher than those of control (non-mulching).7. After two years mulching, the root distribution ratios in soil layers0-20cm,20-40cm,40-60cm with mulching dairy manure were36.22%,30.18%and33.60%; the rootdistribution ratios of mulching wood chips were31.19%,38.27%,30.53%; the root distribution ratios of mulching alfalfa were26.42%,34.91%,38.68%; and the rootdistribution ratios of control (non-mulching) were24.30%,36.59%,39.11%.8. After mulching, the weed numbers of mulching dairy manure, wood chips, alfalfaand control (non-mulching) were7.11plant/m2,5.11plant/m2,5.00plant/m2,60.33plant/m2, those of all mulching treatments had no significant differences; The weedbiomass were30.00g/m2,53.33g/m2,10.00g/m2,416.67g/m2, the weed biomass ofcontrol was significantly higher than mulching treatments and no significant differenceswere observed between each mulching treatment.9. The walnut yields of mulching dairy manure, wood chips, alfalfa and control(non-mulching) were145.14kg/666.7m2,129.00kg/666.7m2,126.49kg/666.7m2,124.71kg/666.7m2and that of mulching dairy manure was significantly higher than othertreatments, while there had no significant differences among the other treatments.10. The fat contents of mulching dairy manure, wood chips, alfalfa and control(non-mulching) were70.55%,68.95%,69.73%,68.91%, there had no significantdifferences among all the treatments; the total protein contents were21.98%,21.53%,21.91%,20.29%, no significant differences were observed among all the treatments; thesoluble protein contents were2.22%,2.15%,2.17%,2.10%and no significant differenceswere observed among all the treatments. |
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