Soil samples were collected from Sankou,Taihuyuan(Xitianmu village) and,Hengfan towns,the main production area of Phyllostachys praecox stands in Lin'an,Zhejiang Province where covered of 3.5×104 hm2 area.Soil profiles were excavated in 1 a,5 a,10 a,15 a planting years of bamboo stands and each with 4 sites replications to study the variation of soil phosphorus content and distribution in due time of intensive management practices by yearly heavy fertilization and 30 cm thick organic mulch in winter season for higher yield and quality of Bamboo shoots.Soil P component was analysed by solution 31P NMR(AVANCE II 300MHZ BRUKER Co.) to give a sight of dynamics of various phosphorus components and its possible impact to soil and water environmental quality.Results indicated that,with the prolong of intensive management years of Phyllostachys praecox stands,the contents of soil total phosphorus(TP),available phosphorus(AP) increased steadily up to P 1.96~2.01 g kg-1 and P 458~468 mg kg-1,respectively.However,the increase of soil organic phosphorus(SOP) was relatively small.But all of the TP,AP,SOP contents showed gradually decrease from top layer > middle layer >> bottom layer in a soil profile which revealed that the soil phosphorus was enriched on the surface layer.The ratio of SOP to TP is relatively low as only 29% ~20% and showed that it was gradually going down as the planting year prolonged.Data from the solution 31P NMR analysis revealed that inorganic orthophosphate was represented a significant proportion of the total P content,and the content of orthophosphate monoesters were lower but they increased with the planting years prolong.While contents of those orthophosphate diesters and pyrophosphate esters were a little,which revealed that the increase of SOP was quite low during the period of studied Phyllostachys praecox stands.Due to the high soil available P in Phyllostachys praecox stands of studied area,we suggested that any further P fertilizer application should be stoped immediately till to the AP lower down to resonable level,soils have accumulated enough P for high yield and quality bamboo shoots production of next 3~5 years,it is not only save the valuable resources of P but also benefit in reduce the potential risk to soil and water pollution.

通过对攀枝花地区气象条件和烤烟生产情况分析,认为该地区特别是半干旱的山区可以通过发展雨水集蓄利用技术,采取适当推迟移栽的生产方式,解决当地烤烟常规移栽时严重缺水导致的烟苗前期生长不良、发育不全、烟叶产低质次的问题。研究表明:选择在径流汇集的部位就地修建敞口的蓄水池,以便同时收集雨水和径流,提高水资源的截留量,在旱季(10月底至翌年5月初)进行薄膜覆盖,可以减少池内储水蒸发损失达35%以上。大田试验研究表明:推迟到6月初移栽,可促进烤烟前期根系生长,不仅生长量明显比常规移栽要大,全生育期仅比常规的推后7d左右,而且也不影响烟叶的采收和烘烤。

雷竹(Phyllostachy Praecox f.preveynalis Chen et Yao)别名雷公竹,是禾本科竹亚科刚竹属竹种,是我国优良笋用散生竹种之一[1].原来主要分布在浙江省临安、德清等地,已有200多年的栽培历史.改革开放以来,推广了以大量施肥和冬季覆盖为主要内容的集约经营技术,使雷竹提早出笋,提高了产量和经济价值[1-2],成为农民致富的一种新兴产业.

Phyllostachys praecoxis a favourite bamboo specieswith highereconomic value forits bamboo shoot as a delicious vegetable. The practice of intensive managementby overfertilizingof complexfertilizer(16∶16∶16, 2.25 thm- 2)and urea(1.125 thm- 2)peryearplusheavierwintermulching(40 thm- 2 of rice strawand 55 thm- 2 of grounded bamboo leaves)every two years starting at 5 years for the higher yield of bamboo shoot and earlier marketing at the Chinese Spring Festival season to gain better price and incomes in Southeast China, especially in Zhejiang Province. The objective of this study is to analyse the temporal and spatial variation of soil organic matters(SOM)in Phyllostachys praecox stands during last 15 years with very intensive cultivation management in Lin'an.Total of 20 soil profileswere sampled in main cultivation region of Sankou Town, choosing 1, 5, 10, 15 and 0 years(paddy fields nearby as the beginning soil Phyllostachys praecox stands as a check) plantation of bamboo stands and each by 4 replications. Results indicated thatwith the increase of plantation year,SOMdropped a little in the beginning(1 year), and then rose up steadily. SOM content in surface layer of 0- 10 cmwere gradually increased from1, to 5 years, then 10 and 15 years, andwere 30.96, 25.55, 26.35, 33.07 and 79.24 gkg- 1 respectively. Very high SOM content in 10 years and 15 years soils were resulted from over fertilization and heavy wintermulching of biomass. SOM spatial distribution in soil profiles showed that it was decreased with the soil depth increase in the layers of surface(0- 10 cm) and subsurface(10- 20 cm), but not in the bottom layer(20- 40 cm), it neither dropped at1 years clearly and nor increased lateron, showed a relative steady situation.It indicated that intensive cultivationmanagementhad vigorously effectonSOMcontentin 0- 10 cm surface and 10- 20 cmsubsurface layerswhere the bamboo shootproduced, butcould notaffectthe deep layerof soil. The effect of high content of SOMin Phyllostachys praecox stands on soil quality and its sustainable use, the significance of carbon sequestration of such high SOM accumulation by this intensive management practices were also discussed.[Ch, 1 fig. 2 tab. 20 ref.]