沙棘林改土培肥作用的研究

通过对沙棘林土壤及枯枝落叶营养状况的测定，结果表明，不同地区、不同林龄沙棘林地土壤和枯枝落叶营养元素含量差异不大，林地土壤中N全、P全、K全、Ca++、Mg++的含量分别为O.0306%-O.2902%、O.0843%-O.1779%、2.1274%-2.8207%，0.0026%-0.0182%、1.3375%×10-4-6.9385%×10-4;N速、P速、K速、CEC值分别为15.167%-52.267%、2.5747%-l4.l980%、78.8735%-33.4135%、8.1860-25.2595mg/kg。枯枝落叶的N全、P全、K全、Ca++、Mg++分别为1.2696%-11.6694%、0.0576%-0.1283%、0.6250%-0.9823%，2.0643%-3.8821%、0.2187%-0.3143%，且不同土层和林龄表现出不同的规律性;沙棘林地土壤中有机质与N、P、K相关性最为密切。沙棘林地营养含量比相应的农田和草地的高得多，表现出明显的改土培肥作用。

Function of Soil Improvement and Fertility for Hippophae rhamnoides Plantations

Determination on nutrient contents in the soil and litters of Hippophae rhamnoides plantations showed that there were no obvious differences to the nutrient percentage contents in the soil and litters of different regions and stand-age. The contents of NT, PT. KT, Ca++ and Mg++ in the soil were 0. 0306%-0. 02902%, 0.0843%-0. 1779%, 2. 1274%-2. 8207%, 0. 0026%-0. 0182% and 1. 3375 X 10-4-6. 9385 X 10-4 respectively. The contents of quick-acting N,P and K and CEC in the soil were 15. 169%-52. 267%,2. 5747%-14. 1980% ,78. 8735%-331. 4135%,and 8. 1860-25. 2595 mg/kg respectively. The contents of NT, PT, KT, Ca++ and Mg++ in the litters were 1. 2696%-11. 6694%,0. 0576%-0. 1283%,0. 6250%-0. 9823%, 2. 0843%-3. 8821% and 0. 2187%-0. 3143% respectively. There were different regular patterns for the contents in the different soil layers and stand-ages. The relationships between organic matter and N,P, K percentage contents in the soil were close. The nutrient percentage contents of Hippophae rhamnoides plantations were much higher than those of farmland and grassland.