Study on mulching cultivation Technology of Phyllostachys pubescens shoot Forest

Study on Mulching Cultivation Technique of Phyllostachys pubescens Forest

Phyllostachys heterocycla (Carr.) Mitford 'Pubescens' is an important natural resource in Xianning. There are 102,300 hm2 bamboo forest in Xianning, including 100,400 hm2 bamboo forest and 260 million bamboo trees. The annual output of bamboo is 25 million, accounting for more than 80% of the whole province. At present, the management mode of Phyllostachys pubescens forest is single, and large-scale cultivation practice of bamboo shoot forest has not been carried out yet. Influenced by its own growth characteristics and market demand, the traditional bamboo forest management mode based on bamboo production is difficult to achieve a great breakthrough in yield and benefit. Therefore, it is imperative to explore a new production and management mode of Phyllostachys pubescens forest to greatly improve its comprehensive benefits. Bamboo shoot mulching cultivation is a bamboo forest management model, which uses straw, chaff and other materials to cover forest land, improves soil temperature through fermentation, changes the natural growth and development law of bamboo shoots, achieves early shooting and increases bamboo forest management benefits. Zhejiang, Fujian, Hunan and other places have carried out relevant research, and some places have applied the research results to production. Hu Weibin [1], Wang Bo [2] and others advanced the shoot time by 54 d and 57 d respectively by mulching, and the shoot yield was also significantly increased; Qiu Yonghua [3] and others significantly increased the winter shoot yield by continuous mulching with chaff + straw for 2 years. From 2015 to 2016, Xianning City Academy of Forestry Sciences carried out experimental research on bamboo forest mulching cultivation to explore the role of bamboo forest mulching technology in increasing yield of bamboo shoot forest, providing technical reference for early and high-yield cultivation of bamboo shoots.

1 Materials and methods

1.1 Site profile

The experimental site is located in Qianshan National Forest Park, Xianning City, Hubei Province, with geographical coordinates of 114°96′E, 29°48′N, elevation of 200 m and slope to northwest. Woodland soil is yellow brown earth, deep fertile soil layer. The experimental site belongs to subtropical monsoon climate zone, with annual mean temperature of 16.8 ℃, extreme maximum temperature of 41.4 ℃, extreme minimum temperature of-15.4 ℃, annual precipitation of 1 700 mm and annual sunshine duration of 1 234.6 h. The bamboo stands were double year bamboo stands with standing density of 165 ~183 trees/667 m2 and average DBH of 10.7 ~11.1 cm.

1.2 trial design

Three treatments and one control (see Table 1) were set up in the experiment, each treatment was repeated for 3 times, and completely randomized block setting was set up, with a total of 12 sample squares, and each sample square area was 270 m2(18 m×15 m).

Table 1 Test design

1.3 data processing

From 2015 to 2016, it will cover two consecutive years, and the coverage work will be completed from mid-November to late November. The surface (0 cm) temperature and underground (20 cm) soil temperature of each treatment were observed continuously and regularly with a right angle geothermometer. The bamboo shoots in covered forest land were dug according to the standard that the chaff had cracks and the tips of bamboo shoots were lifted from the chaff, and the bamboo shoots in control forest land were about 15 cm above the ground. The yield of each shoot was weighed every day. The average data of two years were analyzed statistically, and Excel 2007 was used for data processing and variance analysis.

2 Results and analysis

2.1 Effects of Different Mulching Treatments on Soil Temperature

The observation of soil temperature in different treatments of Phyllostachys pubescens forest showed that mulching could significantly increase soil temperature. The highest temperature of soil in treatment Ⅰ~Ⅲ was 16.0 ℃, 19.5 ℃ and 22.5 ℃, respectively, 4.7 ℃, 8.2 ℃ and 11.2 ℃ higher than that of control (11.3 ℃), and the highest temperature of soil in treatment Ⅰ ~ Ⅲ was 16.0 ℃, 19.0 ℃ and 20.5 ℃, respectively, 4.5 ℃, 7.5 ℃ and 9.0 ℃ higher than that of control (11.5 ℃). The average surface temperature of treatments Ⅰ~Ⅲ was 12.4 ℃, 14.1 ℃, 14.8 ℃, respectively, 6.8 ℃, 8.5 ℃, 9.2 ℃ higher than that of control (5.6 ℃), and the average soil temperature at 20 cm underground was 12.5 ℃, 14.3 ℃, 15.3 ℃, respectively, 5.5 ℃, 7.3 ℃, 8.3 ℃ higher than that of control (7.0 ℃).

It can be seen from Fig. 1 and Fig. 2 that forest cover can improve and maintain soil temperature to a certain extent, and its temperature variation law is basically consistent with air temperature variation, but it is less affected by air temperature. The warming effect of each treatment was as follows: treatment Ⅲ> treatment Ⅱ> treatment Ⅰ>CK. The variance analysis of soil temperature data of different mulch thickness and different soil layers showed that there were significant differences between each treatment and the control (P