【摘要】：設施蔬菜產業(yè)為解決蔬菜供應的季節(jié)性問題,緩解我國城郊人多地少的矛盾,增加農民的收入等方面的貢獻巨大。設施菜地土壤因長期處于“高溫、高濕、頻繁連作、連續(xù)大量施肥、無降水淋洗”等特殊環(huán)境條件下,其理化性質往往不同于露天自然條件下的土壤。土壤有機碳在全球碳循環(huán)中扮演重要角色,其積累轉化過程對全球碳循環(huán)有直接影響。本文選取武漢城郊設施土壤為研究對象,采用野外實地取樣分析與室內模擬實驗相結合的方法,研究了設施土壤有機碳的組成、積累及垂直分布等變化規(guī)律,探討了設施環(huán)境典型條件對設施土壤有機碳轉化的影響及其作用大小。主要結果與進展如下:(1)設施菜地土壤TOC、DOC、MBC和ROOC的含量普遍高于露天菜地。其中土壤TOC、DOC和MBC含量在設施年限1~5年之間變化不大,在5~20年之間,隨著設施年限的增加均逐漸增加。(2)“空心菜-大蒜”輪種模式下的土壤TOC含量比“空心菜-芹菜”輪種模式高出6.1%,而三個采樣時間的MBC含量要分別高出13.5%、9.2%和37.2%,而DOC和ROOC受土壤輪作模式的影響較小。(3)與露天土壤相應土層相比,設施土壤TOC在40 cm以下土層變化不明顯,MBC在60 cm后的土層變化不大,但可DOC和ROOC表現(xiàn)出明顯的耕層積累和垂直下遷現(xiàn)象,在100 cm層次的含量仍高于露天土壤。(4)在4~25℃條件下,溫度升高可增加設施土壤ROOC和MBC的含量,而降低土壤DOC含量;在pH在5.30~8.34的范圍內,土壤酸化可降低其ROOC和MBC的含量,而提高其DOC含量;土壤鹽化程度加重降低了設施土壤DOC、MBC和ROOC的含量。(5)溫度升高、土壤pH越接近中性、土壤鹽化程度加重,這些環(huán)境變化均使設施土壤有機碳碳礦化量降低,而使土壤胡敏酸碳與富里酸碳的比值增加。(6)不同外源性有機碳、外源性磷、溫度、水分和土壤pH這5個因素中,溫度和外源性有機碳種類及其交互作用對土壤有機碳轉化的影響最大,而各影響因素對土壤腐殖質組分轉化的影響在30天的培養(yǎng)時間內并不顯著。
[Abstract]:The facility vegetable industry contributes a lot to solve the seasonal problem of vegetable supply, alleviate the contradiction of large number of people and less land in the suburbs of our country, and increase the income of farmers. The physical and chemical properties of vegetable soil are different from those in open air because of the special environmental conditions such as "high temperature, high humidity, frequent continuous cropping, continuous fertilization and no precipitation leaching" for a long time. Soil organic carbon plays an important role in the global carbon cycle, and its accumulation and transformation process has a direct impact on the global carbon cycle. In this paper, the composition, accumulation and vertical distribution of organic carbon in facility soil were studied by combining field sampling analysis with indoor simulation experiment. The effects of typical conditions of facility environment on organic carbon transformation of greenhouse soil were discussed. The main results and progress are as follows: (1) the contents of TOC,DOC,MBC and ROOC in vegetable soil are generally higher than those in open vegetable field. The contents of TOC,DOC and MBC in soil changed little between 1 ~ 5 years, and between 5 ~ 20 years. With the increase of facility life, the soil TOC content of the model was 6.1 higher than that of the model of "celery". (2) the content of soil TOC was higher than that of "celery" under the rotation pattern of "empty vegetable and garlic", and the content of soil TOC was much higher than that of the model of "celery". However, the MBC content of the three sampling times was higher than that of 13.5and 37.2percent, respectively, while DOC and ROOC were less affected by the soil rotation model. (3) compared with the corresponding soil layers in open-air soil, the content of DOC and ROOC in the three sampling periods were higher than those in the corresponding soil layers. The change of TOC in the soil layer below 40 cm was not obvious, but that in the soil layer after 60 cm of MBC was not obvious, but DOC and ROOC showed obvious accumulation of plough layer and vertical migration. The content of ROOC and MBC in the soil at 100 cm level was still higher than that in the open soil. (4) at 4 ~ 25 鈩，

本文編號：2423872