WBC-VIII-Vol.4 – Resources – Forestry, Plantations and ... - BambuSC

shoot earlier in the winter. Hence, the cultivating area of Lei bamboo has been increasing greatly in the region.
However, with the planting time increased, the bamboo stand degradation occurred and shoot yield decreased
significantly. In the first year of organic material mulching, the yield of bamboo shoot can reach 35 ton per ha,
but it drops to less than 10 ton per hm 2 when the stand degraded after 5 years. Thus, the sustainable bamboo
production becomes a practical problem due to the bamboo growth obstacle. Presently, the area of Lei bamboo
is about 27,000 hm 2 in Lin-an city, however, 1/4 of which is showing degradation with lower production. Some
researchers considered that the main reason of the bamboo degradation was irrational bamboo stand
management that resulted in a weak growth of bamboo and finally to the stand degradation (Jin et al. 1999; Yu
et al. 2001). However, there was no sufficient evidence to elucidate the bamboo degradation with the intensive
fertilization and the organic material mulching technique involved.
The organic material (rice straw and bran) mulching technique was developed by the local agricultural
technician of Lin-an city (Jin et al. 1998). Using this technique, the bamboo shoot yield was improved greatly
and the harvesting time was brought ahead that greatly increased the profit of the bamboo planting. Accordingly,
this technique was extensively used in the region of Lei bamboo plantation and even to other neighboring
provinces. According to our preliminary field investigation, the bamboo tended to degradation after 5 years
using the mulching technique. However, judged from the bamboo growth, no evidence can support the
explanation of bamboo degradation induced by irrational management practices (Yu et al. 2001) because the
bamboos with or without the mulching technique showed no significant difference in growth in the field,
indicating the farmers’ management practices were not greatly different in the field using the technique or not,
especially in the harvesting of bamboo shoot. Because of the large inputs of fertilizers and organic materials
with high C/N ratio, soil acidification can be expected severe in the bamboo plantation soil.
The changes of soil properties with respect to the organic material mulching technique may be responsible for
the bamboo withering. Therefore, the objectives of this study were to investigate the basic physiochemical
properties of soils with bamboo plantation using the mulching technique to provide an evidence for a better
bamboo management. At the same time, the information obtained from this study may be of benefit for us to
understanding the influence of bamboo intensive plantation on soil properties.
Materials and Methods
Study Site Description
The study site is located at Lin-an city, Zhejiang Province of China. This region belongs to the sub-tropical
monsoon zone. The landform here is hilly with elevation around 150 m. The annual mean temperature is 15.9
with a maximum of 41.3 and a minimum of -13.3 . The annual rainfall is 1550 mm with 236 free-frost days.
In this region, the soil type belongs to ferrosols derived from red sandy rock-bed. Lei bamboo (Phyllostachys
praecox) is a local species and was tamed to plant on the former rice field for high yield, so we selected the rice
field plot as the control.
A technique of organic material mulching was developed and adopted in the Lei bamboo production. The
mulching technique uses rice straw and bran, sometimes bamboo leaves as the mulching material. The bamboo
VIII World Bamboo Congress Proceedings Vol 4-58