Research Of Promoting Measures Of Larix Principis-rupprechtii Litter Decomposition

Larix principis-rupprechtii litter amount is larger, and most is difficult decomposition needles litter, poor quality of the substrate, low decomposition rate, cause slow nutrient cycle, led to the plantation soil fertility decline. Therefore, experiment made Larix principis-rupprechtii litter as the research object in Saihanba mechanical forest farm in Hebei province. Through the mixed litter, tending thinning, pyroligneous acid application and nitrogen application four promote measures to research for Larix principis-rupprechtii litter decomposition method, analysis different measures on Larix principis-rupprechtii litter decomposition rate and nutrient content.(1) Larix principis-rupprechtii and Betula platyphylla mixed litter decomposition had obvious role in enhancing Larix principis-rupprechtii litter decomposition rate, weight remaining rates of mixed treatments were significantly than those of PL. Mixed decomposition promoted litter accumulation of N. P element early, inhibited late, had no obvious effect at the end of test, and the impact on the P element was more significant than N elements. Had no significant effect on K element.6L:4B treatment promoted best, weight remaining rate was 12.63% less than PL, decomposition constant was 28.89% larger than PL, turnover period was 18.73% less than PL, P remaining rate was 11.61% less than PL. C/N was 55.56% less and C/P was 43.10% less at the end of the test.(2) Tending thinning had a certain degree role in enhancing Larix principis-rupprechtii litter decomposition rate. Litter weight remaining rates after thinning were significantly lower than control test. Tending thinning promoted the release of the N and P element, no obvious effect on the release of K.20% of thinning intensity promoted best, the weight remaining rate was 11.46% less than control test, decomposition constant was 26.22% larger than control, turnover period was 17.01% smaller than contral. N remaining rate was 15.00% smaller than control, P remaining rate wass 1.69% smaller, C/N was 6.76% smaller and C/P was 22.17% smaller. But when thinning intensity increased to 35%, had inhibitory effect on litter decomposition at the end of the test.(3) Pyroligneous acid had a certain degree role in enhancing Larix principis-rupprechtii litter decomposition rate. Litter weight remaining rates after applying pyroligneous acid were significantly lower than control, and with the increase of pyroligneous acid dilution ratio, also increased the weight remaining rate. When 200 times dilution, promoted the accumulation of N in the litter, low concentration inhibited. Promoted the release of P in litter. When pyroligneous acid concentration was too low or too high, both inhibited the accumulation of K, it was only 400 times dilution, could promote the accumulation of K. When pyroligneous acid diluted 200 times, the promoting effect was best, weight remaining rate was 17.61% smaller than control, decomposition constant was 40.00% larger than contral, turnover period was 26.18% smaller than contral, N remaining rate was 3.53% larger, the P remaining rate was 17.59% smaller. K remaining rate was 9.41% smaller, C/N was 34.32% smaller and C/P was 17.65% smaller at the end of the test.(4) Nitrogen application had no obvious effect in enhancing Larix principis-rupprechtii litter decomposition rate. Nitrogen application promoted the accumulation of N in litter, inhibited the accumulation of P, had no obvious effect on the release of K. When N application was 10g·N·m-2·a-1 promoted best, N remaining rate was 8.55% larger than control. P remaining rate was 29.63% smaller than control, C/N was 20.17% smaller and C/P was 23.84% more than contral at the end of the test.