灌溉方式对梨园土壤水分及产量品质的影响

采用沟灌、畦灌、滴灌、微喷灌和不灌水(CK)5种灌溉方式,通过对比试验研究不同灌溉方式对梨园土壤水分含量、叶片光合参数及果实产量与品质的影响,筛选适宜的节水抗旱灌溉技术。结果表明:(1)果树根层(0～60 cm)土壤含水量表现为微喷灌>滴灌>畦灌>沟灌>CK,微喷灌的蓄水能力显著高于其它灌溉方式;(2)叶片净光合速率表现为微喷灌≥滴灌≥畦灌>沟灌>CK,微喷灌处理的梨树叶片光合作用能力最强,其次是滴灌;(3)增产效果最好的是微喷灌,其次是滴灌,单株产量分别比CK提高了54.98%和44.18%;(4)在果实品质方面,微喷灌和滴灌显著提高了果实的单果质量、可溶性固形物含量及可溶性总糖含量,并且显著降低了果实硬度、含酸量及石细胞含量,两者对果实品质的改善效果明显好于沟灌和畦灌。综合分析表明,微喷灌能够明显改善梨园土壤水分条件和梨树光合能力,显著提高果实产量与品质,是较为理想的节水灌溉技术。     

不同灌溉及施肥方式对酿酒葡萄生长发育及产量品质的影响

针对贺兰山东麓酿酒葡萄栽培中存在的大水大肥等问题,采用田间试验的方法研究不同灌溉和施肥方式下酿酒葡萄长势及产量和品质。结果显示:在常规氮磷钾化肥的基础上增施中微量元素钙镁硫能显著促进新梢生长,增施腐植酸则能显著提高叶绿素含量;灌水方式对葡萄叶片全氮磷钾含量影响不显著,滴灌能显著提升叶柄养分尤其全钾含量;相同施肥条件下沟灌与滴灌产量相当;滴灌条件下进一步增施腐植酸和钙镁硫后产量提高;增施钙镁硫等中量元素可显著增加可溶性糖含量和可溶性固形物,同时明显降低总酸度,改善品质。     

叶绿康球肥对桃树矿质营养和产量的影响

用叶绿康球肥在失绿桃树上进行大田对比试验,通过田间调查和叶片分析,研究了球肥对桃树叶片的复绿效果对叶内矿质营养元素的影响及增产效果。结果表明：施用球肥可使桃树叶片失绿程度降低2～3级,百叶重明显增加,单株产量提高56%～89%,全铁和活性铁含量提高18.7%～19.5%,可降低叶片中N,P,K,Cu和Zn的含量,使这些营养元素与铁的拮抗作用减弱。     

极端干旱区垂直线源灌方式对葡萄生长及水分利用效率的影响

灌溉方式对根系湿润方式的不同会影响作物生长及其对水分的利用效率。以常规滴灌方式为对照,通过田间试验研究了垂直线源灌方式对葡萄生长和水分利用效率的影响,结果表明:葡萄生育关键期灌水前后垂直线源灌方式根层土壤平均含水率可达到田间持水率的75.1%和82.8%,常规滴灌方式为田间持水率的60%和72%;垂直线源灌条件下净光合速率,蒸腾速率,气孔导度均较常规滴灌高,净光合速率均经历了气孔限制和非气孔限制,其中由水分胁迫引起的非气孔限制,垂直线源灌晚于常规滴灌出现,且表现不明显;垂直线源灌方式在地上生物量生长方面略好于常规滴灌方式,但两者未表现出明显差异;垂直线源灌方式较常规滴灌方式在产量上提高了1.2%;叶片水平上的水分利用效率,垂直线源灌方式较常规滴灌方式提高了57.4%。     

肉苁蓉寄生对寄主梭梭体内主要矿质元素含量的影响

对寄生有肉苁蓉的梭梭(HA)与未寄生肉苁蓉的梭梭(CK)不同生长发育时期体内氮、磷、钾、钠、钙、镁、锰、铁等8种矿质营养元素含量的动态变化进行研究。实验结果表明:HA与CK体内的氮、磷、钾、钙、钠以及微量元素铁、锰的含量变化均无显著差异性,只有镁元素二者间差异显著;对于寄生植物肉苁蓉,其体内大量元素氮显著高于HA和CK,磷显著高于HA,而与CK差异不显著,钾、钠、钙、镁、锰、铁6种元素含量均显著性低于HA和CK,同时研究了肉苁蓉寄生后对梭梭体内矿质营养元素的吸收系数的影响,按吸收系数大小排列为N>P>Na>Mg>Ca>K>Mn>Fe。造成以上结果的原因可能与肉苁蓉属于全寄生性植物有关。     

灌水方式对轻度盐化土壤玉米生长及土壤水分的影响

以盆栽玉米为研究对象研究了直接浇灌、滴灌、微润灌等3种灌水方式下玉米的生长、叶绿素含量和光合速率、蒸腾速率等生理生态指标及土壤水分垂直分布的特征,结果表明:灌水方式对玉米生理生态指标有较大影响,苗期滴灌玉米生长较快,拔节前期,微润灌条件下玉米生长最为迅速,滴灌次之,直接浇灌生长最慢;滴灌条件下叶绿素含量最高,拔节期需水旺季时微润灌叶绿素含量最低.三种灌水方式对玉米光合速率的影响为:微润灌＜滴灌＜直接浇灌.土壤水分特征表明:微润灌稳定后土壤水分主要分布在10～ 30 cm土层,滴灌主要分布在10～ 40 cm土层;苗期、拔节期灌水后取样测定的土壤含水率表明,作物根系层内微润灌与滴灌均大于直接浇灌时的土壤含水率.     

长期施用微量元素肥料对土壤微量元素含量的影响

黄土高原旱地17 a施用微量元素肥料定位试验结果表明长期施用微量元素肥料,增强了作物对土壤剖面水分和养分的吸收利用,增加了土壤中相应微量元素的含量,促进了作物对其他元素的吸收利用,导致其他元素有效态含量有所降低.土壤剖面中,有效锌含量为施Zn>施B>施Cu>CK>施Mn,有效铜含量为施Cu>CK>施B>施Zn.各处理土壤有效铁、锰含量均有所降低,有效铁含量为CK>施Cu>施Mn,B,Zn.     

干旱区地下滴灌对加工番茄生长的调控效应

通过3年的田间试验,探索地下滴灌条件下水分对加工番茄生长的调控效应.采用地表滴灌DI及地下滴灌SDI两种处理方式.地面滴灌DI1,Dl2,DI3,处理0～60cm土壤水分含量分别设定田间持水量的(80±5)%,(60±5)%和(40±5)%;地下滴灌SDI,SDI,SDI.处理灌水量及灌水时间与地面滴灌DI1,DI2,DI3相同.结果表明:加工番茄花期后水分处理对地面滴灌及地下滴灌番茄根系生物量、根长密度影响不显著,但盛果期地下滴灌处理根系生物量及根长密度显著增加,且地下滴灌处理根系分布明显比地表滴灌分布均匀;花期后地下滴灌水分亏缺处理植株地上部生长量显著低于地面滴灌相应处理,即SDI2和SDI3显著低于DI2和DI3,而盛果期则相反.适度干旱条件下,地下滴灌总体上单果重、单果数及水分利用效率都显著大于地表滴灌.在土壤水分充足条件下,地下滴灌与地表滴灌相比,对加工番茄生长发育及产量无显著影响,但在轻度干早条件下,地下滴灌显著促进了加工番茄根系及地上部分的生长,显著提高了土壤水分利用效率,提高了加工番茄的产量.     

民勤绿洲不同节水灌溉模式棉花综合效益研究

为了提高民勤绿洲水资源利用率,在该地区棉田进行了滴灌、半固定式喷灌和渠道防渗灌溉3种不同灌溉模式的节水综合效益比较试验。结果表明,与大水漫灌相比,防渗渠灌节水40.4%,滴灌节水49%~55.6%,喷灌节水59.2%;防渗渠灌、滴灌和喷灌分别省工3.6%、16.2%和25.1%;滴灌、喷灌和防渗渠灌分别节电38.5%、31.1%和29.2%。滴灌和防渗渠灌收效明显,可在该地区推广应用。     

外源赤霉素对厚皮甜瓜坐果节位叶片早衰与内源激素含量的影响

采用全株叶片喷施外源赤霉素 (GA₃) 的方法,以黄瓜品种‘迎春’为试材,通过对黄瓜坐果节位叶片中的叶绿素、可溶性蛋白质、抗氧化酶活性、活性氧及内源激素含量等各项生理指标及果实品质指标进行测定,探究GA₃对厚皮甜瓜坐果节位叶片早衰及内源激素含量变化的调控作用,为延缓厚皮甜瓜坐果节位叶片早衰并提高其果实产量和品质提供理论依据。结果显示:与对照相比,叶面喷施50、100和150 mg/L的外源GA₃水溶液可不同程度地增加坐果节位叶片中的叶绿素和可溶性蛋白含量,提高其抗氧化酶活性,降低超氧阴离子产生速率,减缓丙二醛含量的增长,同时抑制脱落酸的增长,提升生长素、赤霉素和玉米素核苷水平,最终显著改善果实产量和品质。通过叶面喷施适宜浓度外源GA₃,对厚皮甜瓜坐果节位叶片抗氧化酶系统和内源激素含量的调控产生积极影响,从而延缓叶片早衰并提高果实产量和品质。在本试验条件下,喷施100 mg/L的外源GA₃水溶液延缓早衰效果最佳,且在各个时期能够使坐果叶片内脱落酸含量分别平均降低19.22%,玉米素核苷、生长素和内源赤霉素含量分别平均升高14.60%、23.50%和56.13%。     

Low soil temperature reducing the yield of drip irrigated rice in arid area by influencing anther development and pollination

Drip irrigation can produce high rice yields with significant water savings; therefore, it is widely used in arid area water-scarce northern China. However, high-frequency irrigation of drip irrigation with low temperature well water leads to low root zone temperature and significantly reduce the rice yield compared to normal temperature water irrigated rice, for example, reservoir water. The main purpose of this paper is to investigate the effects of low soil temperature on the yield reduction of drip irrigated rice in the spike differentiation stage. The experiment set the soil temperatures at 18°C, 24°C and 30°C under two irrigation methods(flood and drip irrigation), respectively. The results showed that, at the 30°C soil temperature, drip irrigation increased total root length by 53% but reduced root water conductivity by 9% compared with flood irrigation. Drip irrigation also increased leaf abscisic acid and proline concentrations by 13% and 5%, respectively. These results indicated that drip irrigated rice was under mild water stress. In the 18°C soil temperature, drip irrigation reduced hydraulic conductivity by 58%, leaf water potential by 40% and leaf net photosynthesis by 25% compared with flood irrigation. The starch concentration in male gametes was also 30% less in the drip irrigation treatment than in the flood irrigation treatment at soil temperature 18°C. Therefore, the main reason for the yield reduction of drip irrigated rice was that the low temperature aggravates the physiological drought of rice and leads to the decrease of starch content in male gametes and low pollination fertilization rate. Low temperature aggravates physiological water deficit in drip irrigated rice and leads to lower starch content in male gametes and low pollination fertilization rate, which is the main reason for the reduced yield of drip irrigated rice. Overall, the results indicated that the low soil temperatures aggravated the water stress that rice was under in the drip irrigated environment, causing declines both in the starch content of male gametes and in pollination rate. Low temperature will ultimately affect the rice yield under drip irrigation.     

Effects of combined drip irrigation and sub-surface pipe drainage on water and salt transport of saline-alkali soil in Xinjiang,China

Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0-200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.     

滴灌条件下核桃园土壤水分动态变化的数值模拟研究

为探究滴灌条件下核桃根系对土壤含水量的影响,试验以8 a生核桃树为研究对象,使用分层分段挖掘法分析核桃根系的空间形态分布,通过构建HYDRUS-2D模型,对有根系吸水下的土壤水分变化进行求解,并利用实测点数据校验2D模型的可用性。经过实际计算与理论分析,得出如下结论:在垂直二维剖面中,水平距树0~30 cm、垂直40~60 cm土层的细根根长密度分布最大,为1 618.216 m·m~(-3)。对比实测数据与模拟数据,结果显示RMSE均小于0.0186 cm~3·cm~(-3),ME绝对值小于0.0108 cm~3·cm~(-3),证明数值模拟效果较好,HYDRUS模型可应用于实际试验研究。将根系模块纳入模型模拟,并比照单独水流模块作用,结果显示根系对土壤含水量产生影响,使体积含水率曲线整体低于单独水作用下的含水率曲线,且两者关系差异性显著。模拟核桃生育前期土壤含水量变化,结果表明灌水后6 d至7 d内,土壤含水量存在明显减小现象,故可将生育前期灌水周期设定为6 d或7 d。     

滴灌条件下成龄核桃根系空间分布特征和模型研究

以阿克苏地区进行地表滴灌的成龄核桃树为研究对象，基于Hydrus 1D软件进行地表滴灌条件下的4种一维根系密度分布函数（实测根系数据模型、指数分布模型、线性分布模型和分段分布模型）进行土壤水分数值模拟研究。结果表明：根系行方向浅层（0~40 cm土层）、中层（50~80 cm土层）、深层（>90 cm）分布差异性极显著（P<0.01），株方向差异性显著（P<0.05）。滴灌条件下，核桃树根系分布主要位于浅层土壤区（0~40 cm），是根系主要吸水部位，占比65%~73%。指数分布模型、线性分布模型和分段分布模型精度均较高，误差在4%范围内；在根系数据缺失条件下，推荐使用线性分布函数和分段分布函数来模拟根系分布。     

Effects of cotton field management practices on soil CO2 emission and C balance in an arid region of Northwest China

Changes in both soil organic C storage and soil respiration in farmland ecosystems may affect atmospheric CO2 concentration and global C cycle. The objective of this field experiment was to study the effects of three crop field management practices on soil CO2 emission and C balance in a cotton field in an arid region of Northwest China. The three management practices were irrigation methods（drip and flood）, stubble managements（stubble-incorporated and stubble-removed） and fertilizer amendments（no fertilizer（CK）, chicken manure（OM）, inorganic N, P and K fertilizer（NPK）, and inorganic fertilizer plus chicken manure（NPK＋OM））. The results showed that within the C pool range, soil CO2 emission during the whole growing season was higher in the drip irrigation treatment than in the corresponding flood irrigation treatment, while soil organic C concentration was larger in the flood irrigation treatment than in the corresponding drip irrigation treatment. Furthermore, soil CO2 emission and organic C concentration were all higher in the stubble-incorporated treatment than in the corresponding stubble-removed treatment, and larger in the NPK＋OM treatment than in the other three fertilizer amendments within the C pool range. The combination of flood irrigation, stubble incorporation and application of either NPK＋OM or OM increased soil organic C concentration in the 0-60 cm soil depth. Calculation of net ecosystem productivity（NEP） under different management practices indicated that the combination of drip irrigation, stubble incorporation and NPK＋OM increased the size of the C pool most, followed by the combination of drip irrigation, stubble incorporation and NPK. In conclusion, management practices have significant impacts on soil CO2 emission, organic C concentration and C balance in cotton fields. Consequently, appropriate management practices, such as the combination of drip irrigation, stubble incorporation, and either NPK＋OM or NPK could increase soil C storage in cotton fie     

盐碱棉田地表-地下接力式滴灌下水盐分布及棉花生长特征

地表-地下接力滴灌是集膜下滴灌和地下滴灌优点于一体的新型节水控盐技术,但目前针对该技术应用效果的研究尚少。针对如何对地表-地下接力式滴灌中的地表滴灌和地下滴灌进行水量分配效果最优这一问题,设置100%地表滴灌(W1)、75%地表滴灌+25%地下滴灌(W2)、50%地表滴灌+50%地下滴灌(W3)、25%地表滴灌+75%地下滴灌(W4)、100%地下滴灌(W5)共计5个处理,比较了不同水量分配下的地表-地下接力式滴灌与单一地表滴灌、单一地下滴灌对盐碱棉田土壤水盐分布和棉花产量的影响。结果表明：(1)W3处理根区土壤含水量分布最均匀,干燥区域面积最小。(2)W4处理窄行区域淋洗范围最大,脱盐效果最显著。(3)W3处理棉花吐絮期总干物质量和籽棉产量最大,分别为112.66 g和9 147 kg·hm^-2;吐絮期总干物质量比W1和W5处理分别提高11.3%和19.1%,籽棉产量比W1和W5处理分别提高14.1%和11.9%。地表-地下接力式滴灌处理下土壤含水量得以显著改善,在对土壤盐分进行淋洗的过程中表现出接力效应,淋洗面积和淋洗效果均有所增大。相比于单一地表滴灌和单一地...     

Effects of temperature,water regime and irrigation system on the release of ascospores of Mycosphaerella nawae,causal agent of circular leaf spot of persimmon

Experiments were conducted under controlled conditions to quantify the effects of temperature, water regime and irrigation system on the release of Mycosphaerella nawae ascospores from leaf litter in Spanish persimmon orchards. The effect of temperature on ascospore release was best described by a Gompertz model. The end of the lag phase of ascospore release occurred at 9·75°C, and the end of the exponential phase at 15·75°C. Few ascospores were discharged from dry leaves wetted with 0·1 or 0·5 mm water, but significant amounts were recovered with 1–50 mm water. About half of the total ascospores were released after three wetting and drying cycles, but 32 cycles were necessary for a complete discharge. No significant difference in ascospore release was detected when the leaf litter was wetted by flood and drip irrigation. However, considering the proportion of soil area wetted in both systems, inoculum release was significantly reduced by drip irrigation. The potential of drip irrigation as a cultural control measure should be investigated.