日光温室滴灌水热调控对土壤氮素动态和酶活性及白菜生长的影响

发布时间：2018-01-02 07:32

本文关键词：日光温室滴灌水热调控对土壤氮素动态和酶活性及白菜生长的影响　出处：《中国水利水电科学研究院》2017年硕士论文　论文类型：学位论文

【摘要】：土壤水热条件是影响作物生长和产量的重要因素,也是近年来灌溉调控和管理研究的关注热点。目前,针对土壤水热调控的研究和应用主要围绕覆膜滴灌技术展开,研究内容主要集中在覆膜对作物耗水规律及水分利用的影响等方面,土壤水热条件变化对滴灌施氮过程及氮素吸收利用影响的研究还很少涉及。此外,对于利用灌溉水温改变土壤水热条件,进而调节作物生长、养分吸收和产量的研究还十分缺乏,仅有的少量研究集中在利用调节灌溉水温改善寒区水稻的生长条件和产量方面。为此开展滴灌条件下土壤水热条件变化对氮素迁移转化及作物吸收过程的研究,揭示不同土壤水热条件下的滴灌水氮调控机制,将为滴灌水氮调控措施在不同土壤水热条件下的制定提供依据。本文以白菜(Brassica pekinensis)为研究对象,于2015和2016年开展日光温室滴灌试验,考虑土壤温度调控措施和施氮量2个因素,土壤温度调控措施设灌溉水加温(保持在30～35℃)、覆膜、覆膜条件下灌溉水加温(保持在30～35℃)和无调节4个水平,施氮量设置0、150和300 kg/hm2三个水平。生育期内监测土壤温度变化、土壤水氮分布和土壤酶活性变化,定期测定白菜株高、球形指数、地上部分干物质质量和吸氮量,研究滴灌水热调控和施氮量对土壤水热、氮素吸收转化和作物生长及产量的影响。主要结论如下:(1)灌溉水加温对土壤温度的调节主要体现在灌水过程中,增温幅度与气温有关,在表层10 cm 土壤中最高可达7℃;灌水结束后土壤温度快速下降,4～5h后与无调节处理基本一致。灌溉水加温与覆膜相结合后,灌水过程中的增温幅度会增大1～2℃,且在灌水结束后土壤温度的下降趋势变缓。在白菜生育期内,仅增加灌溉水温对土壤温度的影响并不明显;而覆膜对土壤温度的影响深度可以达到30cm,尤其对生育前期的土壤温度增加明显,苗期10～30cm 土层的日平均土壤温度可以增加1.4～2.1℃;而覆膜与增加灌溉水温的结合可以明显提高白菜生育后期的土壤温度,结球期10～30cm 土层的日平均土壤温度可以增加1～3℃。(2)覆膜后0～40cm 土层的土壤含水率有明显增加。生育期内各土层土壤的NO3--N含量都随施氮量增加而增加。增加灌溉水温和覆膜都会减少NO2--N在土壤表层的累积量;覆膜可以明显提高0～20cm表层土壤NH4+-N含量。覆膜可以使0～20cm表层土壤有机氮矿化量提高5.7%～38.7%,并且与增加灌溉水温的结合可以对20～40cm深层土壤有机氮矿化量有一定的影响。(3)滴灌水热调控措施和施氮量主要影响0～20cm表层土壤脲酶活性;土壤脲酶活性随施氮量增加而增强;覆膜、增加灌溉水温和覆膜与增加灌溉水温的结合可以使生育期内0～20cm表层土壤脲酶活性分别增强12%～17%、8%～15%和18%～30%。施氮量对土壤天门冬酰胺酶活性没有明显的影响;覆膜可以使0～20和20～40cm 土层土壤天门冬酰胺酶活性分别增强50%～140%和50%～180%倍;覆膜与增加灌溉水温的结合可以使0～20和20～40cm 土层土壤天门冬酰胺酶活性分别增强60%～200%和60%～180%倍。在白菜结球期,土壤脲酶活性与土壤无机氮含量正相关;在白菜莲座期和结球期,土壤天门冬酰胺酶活性与有机氮矿化量和无机氮含量均正相关。(4)白菜株高随施氮量增加有增加的趋势,但在生育后期和收获时处理间差异逐渐减小;覆膜可以使白菜生育前期的株高明显增加。覆膜可以通过改善土壤水热和土壤肥力条件,促进白菜前期生长,提高白菜地上部分干物质质量和吸氮量,进而提高产量;并且与增加灌溉水温结合后,增温和增产效果更明显。(5)为了避免因气温较高而产生热害、虫害等各类病害现象,在滴灌条件下,华北温室大白菜的播种日期可以推迟半个月左右。为了达到节水高产的效果,菜农可以在白菜生育前期采用覆膜的栽培方式改善土壤水热条件,以保证白菜出苗率和前期的生长;在莲座期之后可以采用覆膜与增加灌溉水温(保持在30～35℃)结合的栽培方式提高土壤温度,以避免因温度过低影响作物生长和产量的形成。
[Abstract]:The soil water and heat condition is an important factor affecting the growth and yield of crops, but also in recent years focus on irrigation control and management research. At present, the research and application for water temperature regulation of soil around the drip irrigation technology, the study focused on the aspects of crop mulching on water consumption and water use effect, the change of soil water and heat conditions of drip irrigation and nitrogen uptake and utilization of nitrogen process impact studies also rarely involved. In addition, the use of irrigation water temperature change of soil water and heat conditions, and then adjust crop growth, yield and nutrient uptake studies are very scarce and only few studies concentrated in the use of irrigation water temperature regulation to improve the growth of rice in cold region the condition and yield. Therefore research on water and heat conditions, changes in soil under Drip Irrigation on nitrogen transformation and crop absorption process, reveals the different soil water The thermal condition of the drip irrigation water and nitrogen control mechanism for drip irrigation and nitrogen control measures to provide the basis for the formulation of soil at different hydrothermal conditions. In this paper, Chinese Cabbage (Brassica pekinensis) as the research object, in 2015 and 2016 to carry out drip irrigation in solar greenhouse experiment, control measures and 2 factors of nitrogen into the soil temperature. The soil temperature control measures with irrigation water heating (maintained at 30 to 35 DEG C), plastic film mulching, irrigation water in different conditions (heating at 30 ~ 35 DEG C) and adjusting the 4 level, the amount of nitrogen is set to 0150 and 300 kg/hm2 three level. Monitoring the growth period variation of soil temperature, soil water and nitrogen the distribution and change of soil enzyme activity, measured cabbage plant height, sphericity index, aboveground dry mass and nitrogen uptake, study and nitrogen fertilizer on soil water and heat thermal regulation of drip irrigation, nitrogen uptake and transformation and crop growth and yield were studied. The main conclusions are as follows: (1 ) irrigation water heating regulation on soil temperature is mainly reflected in the irrigation process, the warming rate and temperature. The 10 cm in the surface soil up to 7 DEG C; after irrigation soil temperature decreased rapidly after 4 ~ 5h and no adjustment process is basically the same. The irrigation water heating combined with plastic mulch, irrigation process in the warming rate will increase 1 to 2 DEG C, and the downward trend in the temperature of soil after irrigation in cabbage. Slow growth period, only increase the influence of irrigation water temperature on soil temperature is not obvious; and the effect of film mulching on soil temperature in depth can reach 30cm, especially on the early growth of the soil temperature increased significantly at the seedling stage, the soil layer of 10 ~ 30cm daily average soil temperature can be increased from 1.4 to 2.1 DEG C; and with the increase of mulching and irrigation water temperature and soil temperature can significantly improve the cabbage growth stage, heading stage in 10 ~ 30cm soil layer, the average soil The soil temperature can be increased by 1 ~ 3 degrees. (2) film after 0 ~ 40cm soil layer soil moisture rate increased significantly. The content of NO3--N in the growth period of each soil layer are increased with the increasing of nitrogen rate. The increase of irrigation water temperature and film will reduce the accumulation of NO2--N in soil surface mulching can significantly improve; 0 ~ 20cm soil NH4+-N content. Film can make the 0 ~ 20cm soil organic nitrogen mineralization increased by 5.7% ~ 38.7%, and with increased irrigation water temperature of 20 ~ 40cm deep soil organic nitrogen mineralization has certain effect. (3) drip irrigation water heat control measures and nitrogen fertilizer mainly affected 0 ~ 20cm surface soil urease activity; soil urease activity increased with the increase of nitrogen; film mulching and irrigation water temperature and increase with increasing irrigation water temperature can make the growth period of 0 ~ 20cm soil urease activity were increased from 12% to 17%, and from 8% to 15% 18% ~ 30%. nitrogen fertilizer had no obvious effect on soil L-asparaginase activity; film can make 0~20 and 20 ~ 40cm soil were increased from 50% to 140% asparaginase activity and 50% ~ 180% times; with the increase of mulching and irrigation water temperature can make 0~20 and 20 ~ 40cm soil were enhanced asparaginase activity ~ 200% and 60% ~ 60% 180% times. In the period of Chinese cabbage, soil urease activity and soil inorganic nitrogen content in cabbage is related; rosette stage and the heading stage, the soil nitrogen mineralization L-asparaginase activity and organic and inorganic nitrogen content were positively correlated. (4) the cabbage plant height with the increase of nitrogen content increased, but in the late growth stage when the difference between treatment and harvest decreased gradually; mulching can make Chinese cabbage in early growth stage of plant height increased significantly. Mulching can improve the soil fertility condition of water and soil, promote early cabbage The growth of Chinese cabbage increased aboveground dry mass and nitrogen uptake, and yield; and increase irrigation water temperature with increasing temperature, increasing effect is more obvious. (5) in order to avoid high temperature and thermal damage, and other kinds of disease pest phenomenon under drip irrigation, greenhouse cabbage planting in North China the date may be postponed for about half a month. In order to achieve the effect of water saving and high yield, farmers can in the early growth of the Cabbage Cultivation film to improve soil water and heat conditions, to ensure that the rate of emergence and early growth of Chinese cabbage; in the rosette stage can be used after mulching and irrigation water temperature increase (maintained at 30 to 35 DEG C) combined with cultivation method to improve the soil temperature, in order to avoid the low temperature affect crop growth and yield forming.

【学位授予单位】：中国水利水电科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S275.6;S634

【相似文献】