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Soil microorganisms drive nutrients cycling to a great extent, and they play an essential role in maintaining a stable soil ecosystem and ensuring sustainable forestry development. Land management has been proven to be a real factor in influencing soil quality. The purpose of this study was to investigate the effects of different land management techniques on soil microbial communities. There were four types of land management systems selected for this study: natural masson pine, Phyllostachy pubescens, Phyllostachys praecox, and vegetable. Soils were sampled from these four systems and assayed for soil microbial biomass carbon (MBC), community level substrate utilization pattern, functional diversity, and principle component analysis. Values of MBC were significantly different (P<0.05) from one another in the order of masson pine>Phyllostachy pubescens>Phyllostachys Praecox>vegetable. Analysis of community level substrate utilization pattern indicated that carbon source utilization and total activity by soil microorganisms were greater under the masson pine system than the other three systems (P<0.01). The functional diversities of soil microbial communities characterized as Shannon and McIntosh indexes were much richer in soil under masson pine system; Shannon index was 4.483, 4.241, 4.224, and 3.938 and McIntosh index was 13.51, 7.332, 6.272, and 6.261 for natural masson pine, Phyllostachy pubescens. Phyllostachys praecox, and vegetable systems, respectively. The results from the principle components analysis (PCA), based on the data of optical density (OD) at 120 h of incubation, showed that the value of the first principal component (PC1) of soil for natural masson pine was greater (P<0.05) than those for the other three systems. The difference in scores of the second principal component (PC2) between Phyllostachy pubescens, Phyllostachys praecox, and vegetable were not statistically different. The size and activity of soil microbial communities generally decreased with soil depth, with significant differences in soil MBC, community level substrate utilization pattern, and functional diversity indexes found between A and C horizons (P<0.01). It was concluded that land management systems had a great influence on soil microbial biomass, activity, and functional diversity. [ABSTRACT FROM AUTHOR]

Laboratory experiments were conducted to determine the influence of three types of decomposing fresh organic materials [pig manure (PM), Astagalus sinicus (AS), and Alternanthera philoxeroides (AP)] on dissolution of Fe2O3 and ZnO and also the use of a loamy calcareous soil as an alternative source of iron (Fe) and zinc (Zn). Levels of Fe and Zn concentrations in composting solutions changed with composting time. The maximum levels of solution Fe resulting from the decomposition of the three organic materials were 20, 612, and 348 mg L-1 for PM, AS, and AP, respectively, when the soil was supplied as the Fe source, and 17, 32, and 16 mg L-1 when Fe2O3 was supplied as the Fe source. Corresponding maximum levels of solution Zn were 0.9, 0.7, and 1.3 mg L-1 and 35, 171, and 103 mg L-1 when the soil and ZnO was supplied as the Zn source respectively for the same three organic materials. [ABSTRACT FROM AUTHOR]

Oilseed rape (Brassica napus) is sensitive to low boron (B) supply, and its growth response to B may be influenced by soil temperature. To test the relationship between B and temperature, oilseed rape (cv. Hyola 42) seedlings were grown at 10°C (low) root zone temperature (RZT) with B supply from deficient to adequate B levels until growth of low B plants just began to slow down. Half of the pots were then transferred to 20°C (warm) RZT for 11 days before they were moved back to 10°C RZT for the final 4 days. Both plant dry mass and B uptake increased after plants were exposed to warm RZT. However, plant B deficiency was exacerbated by warm RZT in low B plants because of increased relative growth rate and shoot–root ratio without a commensurate increase in B uptake rate. It is concluded that RZT above the critical threshold for chilling injury in oilseed rape can nevertheless affect the incidence of B deficiency by altering shoot–root ratio and hence the balance between shoot B demand and B uptake. [ABSTRACT FROM AUTHOR]

in order to understand the behavior of water soluble organic matter (WSOM) in soil under different types of forest, soil samples from twenty sites were sampled and analyzed for each forest in the area of Huzhou, China. Each sample was extracted with both cool water (25°C) and hot water (100°C). Without exception, hot water soluble organic carbon (HWSOC) was more than cool water soluble organic carbon (CWSOC). Chinese fir forest soil contained 1.49 times more CWSOC and 1.34 times more HWSOC than did the masson pine forest soil. The CWSOC and HWSOC in soil under Chinese fir forest account for 1.11% and 1.60% of total soil organic carbon (TSOC), and 0.70% and 1.19% under masson pine forest soil, respectively. CWSOC under Chinese fir forest was closely related to SOM and microbial biomass carbon (MBC) (correlation coefficients were 0.474* and 0.482* respectively), HWSOC, however, has little to do with SOM, MBC and soil enzymatic activities. HWSOC under masson pine forest was generally associated with SOM, MBC and sucrase, urease and protease (correlation coefficients were 0.511*, 0.510*, 0.541*, 0.418*, 0.356, respectively), but CWSOC was only closely related to sucrase (0.560*) and protease (0.581**). it is concluded that higher amount of WSOC under Chinese fir forest is not good for soil chemical and biological properties. [ABSTRACT FROM AUTHOR]

Phyllostachy praecox is a major bamboo species which produces a small-type of bamboo shoot, one of the most delicious forest vegetables in China. Emergence of bamboo shoots of Phyllostachy praecox usually begins in late January to early February but most shooting does not occur until March. Mulching in winter is commonly adopted to achieve earlier emergence of the bamboo shoots. However, with mulching the plantation of bamboo trees appears to develop early senescence. This could be a result from "disordered" changes of soil chemical and/or biochemical properties. A field experiment was conducted to understand the mechanism. Three commonly used mulching materials, rice straw (RS), mixture of rice straw and rice grain hulls (RH) and leaves of bamboo trees (BL) were applied in December. A control plot without covering (CK), was also established. Dynamic changes of soil chemical properties and soil enzymatic activities were monitored through winter to spring by collecting soil samples at 25 day intervals. The results showed that changes of soil organic matter (OM), total nitrogen (N) and available phosphorus (P) were similar from winter (December) to early spring (March). Over this time, content of soil OM and N decreased slowly and level of soil available P had little change, in contrast, in spring when it was warm, net loss of soil OM, N and P were much greater. This was coincide with the output of bamboo shoot production. By d100 in April, treatment of BL and CK resulted in the least net loss of soil OM, N and P in comparison with those at d0. And RS and RH did the most. Soil enzymatic activities of hydrogen peroxidase, sucrase, phosphatase, urase and protease were generally higher in mulch treated plots than CK. And soil enzyme activities in BL treated plots were highest. [ABSTRACT FROM AUTHOR]