Soil Water Resources Utilization Limit by Red Plum Apricot
Zhongsheng Guo1,2
1,Institute of Soil and Water Conservation, Northwestern A & F
University,
2,Institute of Soil and Water Conservation, CAS & MWR, Yangling,
China;
26,
Xinong Road,
Yangling,
Shaanxi Province 712100,
P. R. China
Tel. ++86-29-87012411
Fax. ++86-29-8701-2210
Corresponding Author:
zhongshenguo@sohu.com
ABSTRACT:Red
plum apricot is a deciduous fruit tree and the best cash forest in
semiarid loess hilly regions. Since 1995, the distribution area of red
plum apricot spreads in the most of the water-limited regions, China.
The yield, benefits and plantation area of red plum apricot increase
dramatically. But along with the growth of red plum apricot tree, soil
drying appeared and sometime become sever,which influence the
yield,quality and benefits of red plum apricot. At this time, the
relationship between the soil water and red plum apricot growth must be
regulated on Soil Water Resource Use Limitation by Plant and Soil
Moisture Carrying Capacity for Vegetation. However, there are few
studies on the regulation theory. In this study, daily precipitation,
soil water suctions at different soil water content were measured, and
the maximal infiltration depth and the soil water resource use
limitation by red plum apricot was estimated. The results show that
wilting coefficient varies with soil depth from 7.98 in surface soil to
7.1% in 240 cm soil depth, and the maximal infiltration depth is 290
cm, and Soil Water Resources use limit by red plum apricot is 212.7 mm.
When the soil water resource in the maximal infiltration depth is lower
than the limit, the relationship between the soil water and red plum
apricot vegetative growth must be regulated in Red Plum Apricot
plantation for high quality production of red plum apricot.
Keywords: Red plum apricot growth; water-limited regions;soil drying;
soil degradation; wilting coefficient; maximum infiltration depth; Use
Limit of Soil Water Resources by Red plum apricot; high quality
production of red plum apricot
INTRODUCTION
Soil water limits the ecological situation where plant roots grow,
especially in water-limited regions where climate and soil
characteristics set the limits of available water for plant growing.
Soil water equilibrium plays a vital role for restoration
rehabilitation. Therefore, soil water management is very important in
agricultural systems (Asgarzadeh et al. 2014).
In recent years, agricultural production activity has been strenthened
to meet the food need of an increasing population worldwide, the
intensification of agricultural activity coexisted negative
environmental influence (Maharjan et al. 2016). Along with population
increase in the water-limited regions, such as in the semiarid loess
hilly region of Loess plateau, People need a lot of food, fruit, fiber,
etc, and original vegetation has been destroyed and change into
farmland. As a result, forest and vegetation is scarcity, and the loss
of soil and water in the Loess Plateau had become a serious
environmental problem by 1949. Loss of soil and water eroded fertile
surface soil and led to soil fertility and crop productivity reduced,
which influence quality of human life. In order to conserve soil and
water loss, relief of destruction
caused by sandstorms and haze weather, increase crop productivity and
the improvement of ecological environment, the government has been
taking many measures since 1950. In particular, with the implementation
of Three-North
Shelter Forest Program sponsored in 1978 for 50 years, large-scale
afforestation and fruit trees has been carried out
on
the Loess Plateau. As a result of these efforts, great achievements have
been made. The forest coverage fast increased and annual sediment
discharge on the Loess plateau has been reduced from 1.6 billion tons in
the 1970s to 0.31 billion tons in recent years, and the runoff has been
halved.
Because soil in this region is very deep and in the range of 30–80 m
from the surface (zhu et al. 1983), and the groundwater table is also
deep (Yang and Shao, 2000), and without irrigation, soil water mainly
comes from some precipitation penetrating through the canopy. Along with
canopy and the roots development, the interception by canopies increase
and the roots of these plants grow quickly and thus take up water from
considerable soil depths, which reduces the soil water supply and
increases soil water consumption. Consequently, the increased water use
by plants and interception and low infiltration capacity and soil water
recharge rates has led to
serious
soil drying with times going by (Guo and Li 2009). The dried soil
layers(DSL)appeared and then its thickness of DSL increased, and soil
drying widespread (Li 1983; Chen et al. 2007). Serious drying of soil
eventually and poor self-regulation of plant result in soil degradation,
vegetation decline and agriculture failure, which have adverse effects
on sustainable use of soil water resources and the stability of forest
vegetation
ecosystems
(Guo and Shao 2013). Thus we should
take effective measures to regulate the nonequilibrium relationship
between soil water and plant growth (RBSWPG) by reducing the population
quantity or density of indicator plants in a plant community on soil
water carrying capacity for vegetation (SWCCV) on the Loess Plateau to
balance the soil water recharge and soil water consumption in plantation
(Guo and Shao 2003; Guo 2014,2021) because soil in this region range
from 30 to 80 m from the surface (zhu et al. 1983), and the groundwater
table is also deep (Yang and Shao 2000),without irrigation.
The concept of soil water resources come in 1985 (Budagovski 1985;
Budagovski and Busarova 1992) after Lvovich proposed the concept of
overall soil moistening in 1980. Soil water resources have different
meaning in different field, such as Geology, Soil Science, Agriculture,
Forestry and Animal Husbandry. In order to meet the need of different
specialty, soil water resources can be classified into static soil water
resources and dynamic soil water resources. Static soil water resources
include generalized and narrow soil water resources. The generalized
soil water resources refers the water storage in the soil from surface
soil to water table, and narrow soil water resources refers the water
storage in the root zone soil, and dynamic soil water resources refers
the antecedent soil storage plus the soil water supply from
precipitation in the growing season for
deciduous plant or a year
for evergreen plants. Soil water resources are renewable water
resources, a component of water resources (Guo 2014).
The state of vertical distribution of soil water in the root soil zone
space influence plant growth. Since drought is a recurring natural
phenomenon, and the soil in which plant root distribute resembles a
reservoirs and have the storage capacity of water, which have the
buffering effect of soil drying on plant growth, the effects of water
stress on plant growth vary with the their gravity in these regions.
Soil Water Resources Use Limit by Plant is the soil water storage in the
maximum infiltration depth(MID) when soil water content in all of the
soil layers of the MID equals wilting coefficient (Guo 2010, 2014 ).We
do not regulate the relationship as soil drought happens until the soil
water resources reduce to a degree (Soil Water Resources Use Limit by
Plant ) because when soil water resources in the maximum infiltration
depth equal Soil Water Resources Use Limit by Plant, soil water
seriously influence plant growth if the duration dry climate continue
surpass the key period of regulation of the relationship between soil
water and plant growth because plant have some self-regulation power .
Red plum apricot is a deciduous fruit tree and the best cash forest in
semiarid loess hilly regions. Since having been selected as good
varieties to popularize in 1995, the distribution area of red plum
apricot spreads from Guyuan county to the whole Ningxia, and then to
Gansu province and so on in the most of the water-limited regions,
China,the yield, benefits and planting area of red plum apricot
increase doubly. But along with the growth of red plum apricot and
precipitation, sometime soil drying become severer. Once serious drying
happens, which led to the change of red plum apricot tree leaf colour
from green to yellow or croci and drop earlier of the leaf. If serious
drying happens in the fruit expansion stage, the size of red plum
apricot fruit cannot expand to normal size, which influence the yield,
quality and economic benefits of red plum apricot forest. At this time,
the relationship between the soil water and red plum apricot growth must
be regulated on Soil Water Resources Use Limit by Plant and Soil Water
Carrying Capacity for Vegetation to reduce or evade the bad influence of
soil drought on the yield and benefits of red plum apricot (Guo
2014,2021). However, there are few studies of Use Limit of Soil Water by
red plum apricot.
In the present work, the study aims at achieving these objectives: (1)
the changes of cumulative infiltration depths with time and the maximum
cumulative infiltration depth in the red plum apricot forest ; (2)
Change of wilting coefficient with soil depth up to maximum infiltration
depth; and (3) Use Limit of soil Water by red plum apricot.
Methods