水保所知识产出(1956---)知识库

本研究采用野外盆栽和定位试验相结合的方法，在陕西省榆林市米脂县红枣节水
示范基地对梨枣树的耐旱性及其平茬后对土壤水分响应的机制进行了试验研究。试验
主要包括两方面内容：一是在连续不供水条件下研究梨枣萎蔫致死的过程；二是连续
2 年（2012 年、2013 年）在不同生育期分别设置 4 个不同的水势水平，研究平茬后梨
枣对土壤水分的响应。初步得出以下结论：
（1）梨枣的初始萎蔫系数平均为 2.49%，表征萎蔫系数平均为 1.49%。梨枣无论
相对其它种类植物还是枣树不同品种的萎蔫系数都要小，具有很强的抗旱性。梨枣的
耐旱致死点为 1.25%，致死时间为 135±11 天。梨枣的永久萎蔫系数在 1.25%与 1.49%
之间，是一个很小的数值范围，而不是某个确定的值。
（2）用表征永久萎蔫系数来描述苗木的抗旱性更为确切。梨枣的表征永久萎蔫系
数要比真正的永久萎蔫系数更有实际的应用价值。当土壤含水量达到表征萎蔫系数时
对植株复水则能使植株免于死亡的危险。在自然条件下，陕北梨枣不会干旱胁迫致死。
（3）在萌芽开花期，平茬有利于增强树势与提高坐果率。梨枣平茬当年在萌芽开
花期的树高与冠幅均大于平茬前。平茬后梨枣的枣吊平均长度、枣吊数量、叶面积平
均值均小于平茬前。平茬后梨枣的花芽数量比平茬前减少 52.46%，但是坐果率却提高
1.69 倍。
（4）在萌芽开花期，平茬后耗水小于平茬前。平茬后土壤质量含水量较平茬前升
高 2.88%，达到了节水和提高水分利用效率的目的。平茬后萌芽展叶期的适宜水势范
围为-41～-69kPa，开花期的适宜水势范围为-59～-72kPa。开花期-72～-112kPa 的水势
范围有利于梨枣平茬后开花期的坐果，当梨枣萌芽开花期的土壤水势大于-461kPa 时，
不会影响梨枣茎秆的生长。5）在果实生长期，高水分处理下平茬有利于提高产量。高水分处理 T1 平茬后
的落果率比平茬前稍高 4.3%，但是单果重增加 40.8%，增产 29.6%。稍高水分处理 T3
平茬后比平茬前的单株产量也是升高的，增产 28.5%，但是平茬后平均水势达到
-97.0KPa 时（T2 与 T4 处理）的单株产量比平茬前产量下降。
（6）在果实生长期，在保持产量相同时，平茬有利于减少灌水量与耗水量。平茬
后虽然整体的平均落果率升高 11.1%，但是果实数量增大了 2.8%，整体产量基本不变。
平茬前后两年产量基本一致的情况下，平茬后的灌水量由 201.4mm 下降到 108.0mm
减少了 46.4%，耗水量由 172.8mm 下降到 149.4mm 减少了 13.5%，这个结果对于干旱
少雨的陕北优质丰产红枣林的发展与减缓土壤层干化现象具有重要意义。
（7）在果实生长期，当平茬梨枣的平均土壤水势低于-215.8KPa，会影响梨枣的
正常生长与果实的正常发育，出现高落果率低单果重的不良现象。在果实快速生长期，
当平均土壤水势低于-287.2KPa 时，平茬梨枣的茎秆出现萎缩现象不能复原。平茬梨
枣在果实生长期的适宜水势范围为-45KPa～-61KPa。
关键词：梨枣；土壤水势；平茬；耐旱致死点；耐旱性

To investigate the drought tolerance of pear-jujube (Ziziphus jujuba Mill.) trees and their
responses to soil water moisture after stumping, pot and field experiments had been
conducted in the Jujube Water-saving Demonstration located in Mizhi County, Yulin City,
Shaanxi Province in China. This study included two main contents. First, the process from
wilting to death of pear-jujube under continuous water stress was studied. Next, the
responses of pear-jujube trees to different soil water moistures after stumping were studied
with four different soil water treatments in two years. Some preliminary conclusions have
been drawn as follows.
(1) The average value of initial wilting coefficient of pear-jujube was 2.49%, while the
average value of apparent permanent wilting index was 1.49%. Pear-jujube had strong
ability of drought resistance since the wilting coefficient of pear-jujube was much lower
than that of other jujube varieties or plant species. In addition, the lethal drought point of
pear-jujube was 1.25% and lethal time was 135 ± 11 days. The permanent wilting
coefficients of pear-jujube varied from 1.25% to 1.49%, which represented a narrow range
of moisture contents rather than a certain value.
(2) It was correct to use the apparent permanent wilting index to describe the ability of
drought resistance of trees. The apparent permanent wilting index of pear-jujube was more
practically valuable than the real permanent wilting coefficient. Rewatering the plant at its
apparent permanent wilting index could keep it from the risk of death. Under natural
conditions, drought stress usually could not lead pear-jujube to dead.
(3) At the budding and flowering stages, stumping not only strengthened the growth of
jujube tree but also improved fruit set percentage. The height and crown width of
pear-jujube trees were higher than those before stumping in the very year. The average
length and number of bearing braches and average leaf areas were all lower than those
before stumping. The number of flower bud decreased by 52.4% after stumping, while the
fruit set percentage increased by 1.69 times.  (4) At the budding and flowering stages, post-stumping water consumption of
pear-jujube trees was smaller than that of pre-stumping. The soil water moisture of
post-stumping increased by 2.88% compared with that of pre-stumping. The purposes of
saving water and improvement of water use efficiency could be achieved. The suitable soil
water potential was -41～-69 kPa during the shoot period after stumping. While, the
suitable soil water potential was -59～-72 kPa for pear-jujube during the flowering period.
Moreover, it was useful for post-stumping pear-jujube trees to set fruit when suitable soil
potential was -72～-112 kPa. The growth of stem was not affected when soil water potential
was greater than -461 kPa.
(5) During fruit development period, stumping improved yield in treatments of high
water moisture. Under the treatment T1 with highest water moisture, the post-stumping fruit
abscission rate was a little greater than that of pre-stumping, while the single fruit weight
and yield increased by 40.8% and 29.6%. The single fruit weight of treatment T3 increased
by 28.5% after stumping. However, the yields of T2 and T4 declined when the average level
of water potential reached -97.0 kPa.
(6) Stumping could reduce the amount of irrigation and water consumption, while
maintaining jujube fruit production at the same level. Although the average fruit drop rate
increased by 11.1% after stumping, the number of fruits increased by 2.8% and the overall
yield remained stable. At the same time, the amount of irrigation decreased from 201.4 to
108.0 mm, or 46.4%. Water consumption decreased from 172.8 to 149.4 mm, or 13.5% after
stumping. This is important for the development of jujube forests of high yield and quality
and the alleviation of soil desiccation to ease in the dry and rainless North Shaanxi.
(7) At fruit development period, normal growth and development of pear-jujube would
be affected after stumping when the average level of water potential was below -215.8 kPa.
High rate of fruit drop and low unit fruit weight could occur. At fast-fruit growing stage, the
atrophy of trunk would not rehabilitate after stumping when the average water potential was
below -287.2 kPa. The suitable soil water potential for fruit development was -45.0～-61.0
kPa for pear-jujube after stumping.
Key words: pear-jujube, soil water potential, stumping, drought lethal point, drought
tolerance