【作者】 周佳民；

【导师】 江立庚；

【作者基本信息】 广西大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 为了探讨免耕对水稻根系生长、生理特性及根际微生态的影响,以籼型三系杂交水稻金优253为试验材料,于2006年晚季和2007年早季分别进行根箱栽培试验。试验设置免耕栽培、常耕栽培、分根栽培三个处理,在拔节期、灌浆期分别取样测定根系生长量及其SOD、POD、CAT等酶的活性及MDA含量,同步取根际和非根际土壤测定土壤pH值、养分含量及土壤酶活性。成熟期测定产量。研究结果表明:免耕栽培水稻各生育期的生物量低于常耕栽培,除2007年早季成熟期外,处理间差异达极显著水平。无论是2007年早季还是2006年晚季,免耕栽培水稻产量高于常耕栽培水稻,但产量差异不显著。免耕栽培水稻根系在生育前期的生长量较小,根冠比明显小于常耕栽培水稻,但生育后期根冠比与常耕栽培水稻相等,甚至高于常耕栽培水稻根冠比。免耕栽培水稻根系或分根栽培中免耕侧根系的SOD、CAT、POD酶活性在拔节期比常耕栽培水稻根系或分根栽培常耕侧根系SOD、CAT、POD活性低,其MDA含量比常耕栽培水稻根系或分根栽培中常耕侧根系MDA含量高,相反,免耕栽培水稻根系或分根栽培中免耕区根系的SOD、CAT、POD酶活性在灌浆期比常耕栽培水稻根系或分根栽培中常耕侧根系SOD、CAT、POD活性高,其MDA含量比常耕栽培水稻根系或分根栽培中常耕侧根系CAT活性低。这表明,常耕栽培水稻根系优势主要在生育前期,而免耕栽培水稻根系的优势主要表现在生育中、后期。水稻根际土壤的pH值明显低于非根际土壤pH值。免耕水稻根际pH值在拔节期显著低于常耕栽培水稻,但在灌浆期却高于常耕栽培水稻。水稻根际土壤的碱解氮和速效钾含量比非根际土壤的低,而有效磷的含量比非根际土壤的高。与常耕水稻相比,免耕水稻根际的碱解氮含量较低,而速效钾和有效磷含量较高。在单一栽培方式下,常耕栽培水稻根际土壤酶(蛋白酶、脲酶、淀粉酶)的活性高于免耕栽培水稻;在分根栽培中,常耕侧土壤酶(蛋白酶、脲酶、淀粉酶)活性高于免耕侧。非根际土壤酶活性的变化趋势与根际土壤相同。更多还原

【Abstract】 In order to investigate influence of no-tillage on root growth, physiological characters and rhizhospheric micro-ecosystem in Rice, rhizobox experiments with three treatments, no-tillage, conventional tillage and root separation tillage, were conducted with Jinyou 253 as experimental materials in the late season of 2006 and early season of 2007, respectively. The dry weight, activity of SOD, POD and CAT as well as MAD content of the root were determined at the elongation and grain-filling stage, respectively. In the meantime, the nutrients contents and enzymes activities of the rhizhophere and bulk soil were determined. And the yield was measured at the maturing stage. The results were showed as follows:The biomass of no-tillage rice was lower than that of conventional tillage rice at various growth stages, and the differences were significant expect that at the maturing stage in the early season of 2007. And the yield of no-tillage rice was higher than that of conventional tillage rice in both the late season of 2006 and the early season of 2007, but the difference was not significant.The dry weight of the roots of no-tillage rice was small and its root/shoot ratio was significantly lower than that of conventional tillage rice at the early stage, while the root/shoot ratio of no-tillage rice was equal to or even higher than that of conventional tillage rice at the later stage. At the elongation stage, the activities of SOD, POD and CAT in the roots of no-tillage or no-tillage area of root separation tillage were lower than that of conventional tillage or conventional tillage area of root separation tillage, respectively, while the content of MDA in the roots of no-tillage or no-tillage area of root separation tillage was higher than that of conventional tillage or conventional tillage area of root separation tillage, respectively. At the grain-filling stage, the activities of SOD, POD and CAT in the roots of no-tillage or no-tillage area of root separation tillage were higher than that of conventional tillage or conventional tillage area of root separation tillage, respectively, while the content of MDA in the roots of no-tillage or no-tillage area of root separation tillage was lower than that of conventional tillage or conventional tillage area of root separation tillage, respectively. Therefore, root superiority were observed at the early growth period for convensional tillage rice, while it appeared at middle or late growth period for no-tillage rice.The pH in rhizhophere soil was significantly lower than that in bulk soil of paddy fields. The pH in rhizhophere soil of no-tillage rice was significantly lower than that of conventional tillage rice at elongation stage, while the pH in rhizhophere soil of no-tillage rice was significantly higher than that of conventional tillage rice at grain-filling stage. The available N and P in rhizhophere soil were lower than that in bulk soil of paddy fields, while the available K in rhizhophere soil was higher than that in bulk soil of paddy fields. The available N was higher and the available P and K were lower in the in rhizhophere soil of no-tillage rice compared with that of conventional tillage rice.The changing trend of invertase (protease, urease, amylase) activity in bulk soil was similar with that in rhizhophere soil. The invertase activity in bulk soil of conventional tillage was higher than that of no-tillage at both jointing and grain-filling stages. In the root separating cultivation, the invertase activity of conventional tillage was higher than that of no-tillage.更多还原