CN114051898A - Planting method for protecting seedlings and saving water of alfalfa in windy and sandy land - Google Patents

Abstract

The invention discloses a planting method for protecting seedlings and saving water of alfalfa in windy and sandy lands, which comprises the following steps of 1, arranging an underground drip tape by adopting an underground drip tape tube distributor, wherein the buried depth of the drip tape is 20cm, the drip tape is of an embedded patch type, the distance between drippers is 20-40cm, the flow rate of the drippers is 1.5-3.0l/h, the distance between the drip tapes is 60-75cm, and after the drip tape is arranged, buried branches, dry tubes and various connecting pieces are installed for later use; step 2, planting winter wheat, performing field management according to a drip irrigation wheat planting rule, and harvesting stubble remaining height of 20-30 cm; step 3, adopting a drill seeder to sow the alfalfa in a no-tillage way, wherein the row spacing is 15cm, the sowing depth is 1-2cm, and the sowing quantity of the alfalfa is 15-30 kg/hm²(ii) a Step 4, laying micro-spraying belts on the sowed alfalfa ground at a distance of 5-6m for seedling stage irrigation,the irrigation quantity is 75-150m³/hm²The irrigation time is 30-60 minutes, and the rotation irrigation period is adjusted according to the weather conditions such as air temperature, rainfall and the like; step 5, after the alfalfa grows for 90 days, removing the micro-spraying belt, cutting, irrigating for 1 time every 7-10 days by using an underground drip irrigation device, wherein the irrigation amount is 600-³/hm²。

Description

Planting method for protecting seedlings and saving water of alfalfa in windy and sandy land

Technical Field

The invention relates to the fields of seedling protection, interplanting and efficient water conservation of alfalfa in sandy land, in particular to a seedling protection and water conservation planting method of alfalfa in sandy land.

Background

In northwest China, particularly in farmlands near the edges of deserts, soil is high in sand content, loose in soil texture, poor in water retention, high in surface temperature and high in seasonal wind and sand, and is not beneficial to planting crops and forage grass. The alfalfa is a perennial pasture with the largest cultivation area in China, the seedling period is about 60 days long and the growth is slow, the alfalfa seeds are small, the sowing depth is required to be shallow, generally 1-2cm, and the alfalfa seeds are easily subjected to wind erosion under the condition that the ground is not covered by plants during sand planting, and the roots of seedlings are exposed or even pulled up by root-linking when the seedlings suffer from wind damage in the seedling period; in addition, the surface temperature of the sandy land can reach more than 60 ℃ in summer, and the alfalfa seedlings are easily scalded by high temperature and heat radiation, so that sand wind and high temperature are the main reasons of planting failure of the sandy land alfalfa and the main technical difficulty of planting the sandy land alfalfa. Literature search reveals: as the windy and sandy land has the characteristics of frequent strong wind in winter and spring, loose soil, easy wind erosion, poor water and fertilizer holding capacity and the like, the alfalfa in the windy and sandy land has a plurality of problems in safe production and is difficult to be successfully planted (Zhao Yan et al, 2016). Because the alfalfa seeds are small and grow slowly in the seedling stage, sand storm can easily erode the topsoil layer of the sand land, so that the alfalfa seedlings are naked and killed, and even directly blown away by the sand storm (Wangman, 2021). As the sand blown by the wind near the desert has high gravel content and the gravel absorbs heat quickly, the temperature in summer is higher than 40 ℃, the extreme temperature of the ground surface is even higher than 70 ℃ (Zingiber officinale, 2020; Liu Kalu et al, 2021), and the seedling temperature of the alfalfa exceeds 35 ℃, the metabolism and the growth and development of the alfalfa can be influenced, and the alfalfa production is influenced (Zhao Yan et al, 2015), the main reason is that the light and pigment content is reduced by the high temperature and the photoreaction center on thylakoid is damaged, so that the PS function is reduced or even completely lost (Wise et al, 2004; Ning Li Yi et al, 2012).

The contents of the above documents show that wind erosion and over-high surface temperature are main limiting factors influencing the planting of the alfalfa in the windy and sandy land, and the reduction of the wind erosion and the reduction of the surface temperature through technical measures are the key points for the successful planting of the alfalfa in the windy and sandy land. In areas with large wind sand, crops with high growth speed and strong wind resistance are frequently interplanted with the alfalfa in production, and the wind sand resistance of the alfalfa is improved by using the protective crops as windbreak.

Disclosure of Invention

The invention aims to provide a planting method for protecting seedlings and saving water of alfalfa in windy and sandy land, which can effectively resist windy and sandy erosion, improve the survival rate of alfalfa seedlings in windy and sandy land, effectively irrigate alfalfa seedlings and improve the yield and the water utilization efficiency of alfalfa hay.

The invention aims to realize the planting method for protecting seedlings and saving water of the alfalfa in the windy and sandy land, which is implemented by sequentially adopting the following operation steps:

step 1, an underground drip irrigation tape is distributed by adopting an underground drip irrigation pipe distributor, the buried depth of the drip irrigation tape is 20cm, the drip irrigation tape is of an internal patch type, the distance between drippers is 20-40cm, the flow rate of the drippers is 1.5-3.0l/h, the distance between the drip irrigation tapes is 60-75cm, and after the distribution of the drip irrigation tape is finished, buried branch pipes, dry pipes and various connecting pieces are installed for later use;

step 2, planting winter wheat, performing field management according to a drip irrigation wheat planting rule, and harvesting stubble remaining height of 20-30 cm;

step 3, adopting a drill seeder to sow the alfalfa in a no-tillage way, wherein the row spacing is 15cm, the sowing depth is 1-2cm, and the sowing quantity of the alfalfa is 15-30 kg/hm²；

Step 4, laying micro-spraying belts on the well-sowed alfalfa ground, wherein the micro-spraying belts are communicated with the buried branch pipes and the trunk pipes in the step 1, the spacing between the micro-spraying belts is 5-6m, the micro-spraying belts are used for seedling stage irrigation, and the irrigation amount is 75-150m³/hm²The watering time is 30-60 minutes according to the days of air temperature, rainfall and the likeAdjusting the rotation period under the condition of air;

step 5, after the alfalfa grows for 90 days, removing the micro-spraying belt, cutting, irrigating for 1 time every 7-10 days by using an underground drip irrigation device, wherein the irrigation amount is 600-³/hm²。

The action mechanism of the invention is as follows:

(1) the winter wheat stubble is used as a windbreak, and the double protection effects of wind and sand prevention and shading can be achieved for the alfalfa seedlings;

(2) according to the characteristics of the sand blown by the wind and the growth habit of the alfalfa, different irrigation modes are selected at different development stages of the alfalfa, and under the conditions that the root system of the alfalfa is shallow at the seedling stage, the alfalfa is not high-temperature resistant and weak in wind resistance, the micro-spray irrigation which is short in irrigation time consumption and rapid in surface temperature reduction is selected to play a role in reducing the temperature and protecting the seedling, the irrigation depth can be changed from shallow to deep according to the growth condition of the root system of the alfalfa, the deep leakage of water and fertilizer is reduced, an underground drip irrigation device which is higher in water utilization efficiency and simple and convenient to operate is used after the alfalfa grows for 90 days, and the role in improving the water utilization efficiency is played;

(3) the underground pipe network systems (including main pipes, branch pipes and the like) of the two irrigation modes are a common system, after the seedling stage of alfalfa, only the surface micro-spraying belt needs to be removed, and the drip irrigation hose is connected with an underground pipe network, so that the cost of the surface micro-spraying belt is only 100 yuan/mu, the surface micro-spraying belt can be recycled, and the operation is simple;

(4) the roots of the adult alfalfa are developed, and due to the fact that the roots of the crops are water-oriented, when the method is adopted, the width of the underground drip irrigation tape can be increased to 60-75cm (the width of the traditional method is 45-60 cm), the irrigation effect is not influenced, and the cost of a drip irrigation system can be reduced by about 15%;

(5) as the micro-spray irrigation is adopted in the seedling stage, the root system of the alfalfa is deeply buried underground (the root system of the alfalfa of 90 days old can reach 60 cm) when the drip irrigation system is started, the drip irrigation belt can be buried to be less than 20cm without influencing the growth of the alfalfa when the method is adopted, the water saving (the surface transpiration is reduced) is facilitated, and the damage of the drip irrigation system caused by the harvest operation of the alfalfa is reduced (the drip irrigation belt is easily damaged due to mowing, raking and pulling when the buried depth is shallow).

In conclusion, the method is suitable for alfalfa planting areas with large wind sand at the edges of deserts. The irrigation can quickly reduce the surface temperature and simultaneously prevent the physiological drought of the alfalfa caused by high temperature; increasing irrigation frequency has important significance for growing alfalfa in seedling stage, however, water resources at desert edges are deficient, and irrigation aims at saving water, reducing consumption and improving water utilization efficiency. Underground drip irrigation is the most effective water-saving irrigation mode for perennial pasture, has obvious water-saving and consumption-reducing effects, but the existing underground drip irrigation mode has poor water retention due to loose texture of sand soil, and has extremely poor capability of permeating water in the lower soil layer into surface soil through capillary phenomenon, so that the underground drip irrigation mode is not suitable for seedling-stage production of the alfalfa in the sand. The micro-spraying can rapidly increase the surface and air humidity and reduce the temperature through high-frequency irrigation, and is an ideal irrigation mode for the seedling stage of the alfalfa in the sandy land. After the seedling stage (about 90 days), the alfalfa starts to grow rapidly, the plants are increased, the leaf amount is increased, the micro-spray irrigation is not uniform due to the blocking of branches and leaves, the micro-spray irrigation is higher than the drip irrigation ground surface evapotranspiration, the root system of the alfalfa is deep into the soil at the moment, the moisture of the soil at the lower layer can be absorbed, the resistance to wind sand and high temperature is obviously enhanced, and therefore the underground drip irrigation is the first choice of the adult alfalfa irrigation mode.

The stubble after wheat harvesting can play a role in wind prevention and sand fixation, two irrigation modes are adopted according to the special environment of sand land and the growth and development characteristics of alfalfa, micro-spray irrigation is adopted in the seedling stage, the purpose is that the surface temperature can be quickly reduced, the rotation irrigation period can be shortened according to the growing characteristics of the seedling stage of the alfalfa, the irrigation can be carried out once or twice a day in high-temperature seasons, the irrigation depth is controlled to be 0-10cm, the drip irrigation can not be carried out, after the alfalfa passes through the seedling (about 90 days), the root system is deeply buried, the high temperature and sand wind resistance is stronger, the mission of a micro-spraying system is finished, at this time, the surface micro-spraying belt can be removed, and the buried drip irrigation system is used for irrigation, so that the alfalfa can be sown at the edge of the desert in spring, summer and autumn, the seedling protection rate of the alfalfa reaches over 90 percent, and meanwhile, the water-saving and consumption-reducing effects are very obvious.

Detailed Description

A planting method for protecting seedlings and saving water of alfalfa in windy and sandy land is implemented by sequentially adopting the following operation steps:

step 1, an underground drip irrigation tape is distributed by adopting an underground drip irrigation pipe distributor, the buried depth of the drip irrigation tape is 20cm, the drip irrigation tape is of an internal patch type, the distance between drippers is 20-40cm, the flow rate of the drippers is 1.5-3.0l/h, the distance between the drip irrigation tapes is 60-75cm, and after the distribution of the drip irrigation tape is finished, buried branch pipes, dry pipes and various connecting pieces are installed for later use;

step 2, planting winter wheat, performing field management according to a drip irrigation wheat planting rule, and harvesting stubble remaining height of 20-30 cm;

step 3, adopting a drill seeder to sow the alfalfa in a no-tillage way, wherein the row spacing is 15cm, the sowing depth is 1-2cm, and the sowing quantity of the alfalfa is 15-30 kg/hm²；

Step 4, laying micro-spraying belts on the well-sowed alfalfa ground, wherein the micro-spraying belts are communicated with the buried branch pipes and the trunk pipes in the step 1, the spacing between the micro-spraying belts is 5-6m, the micro-spraying belts are used for seedling stage irrigation, and the irrigation amount is 75-150m³/hm²The irrigation time is 30-60 minutes, and the rotation irrigation period is adjusted according to the weather conditions such as air temperature, rainfall and the like;

step 5, after the alfalfa grows for 90 days, removing the micro-spraying belt, cutting, irrigating for 1 time every 7-10 days by using an underground drip irrigation device, wherein the irrigation amount is 600-³/hm²。

Example (b):

the implementation method comprises the following steps: the area of the Xinjiang Hetian is 50 mu;

(1) selecting Xindong No. 22 wheat as a previous crop, sowing for 9, 10 and 2018, and applying 30 kg/mu of diammonium phosphate before sowing;

(2) harvesting winter wheat in 2019 in 20 months in 6 months, wherein the stubble height is 25cm-30cm, in 24 months in 6 months, underground drip irrigation devices are arranged on wheat stubble ground, the buried depth of drip irrigation belts is 20cm, the drip irrigation belts adopt an embedded patch type, the distance between the drip irrigation belts is 60cm, and the drip irrigation belts are used for standby after arrangement;

(3) adopting a drill seeder to sow the alfalfa, wherein the row spacing is 20cm, the sowing depth is 1-2cm, and the sowing quantity is 22.5 kg/hm²The time is 6 months and 26 days;

(4) micro-spraying belts are arranged on the well-sowed alfalfa ground, the distance between the micro-spraying belts is 6m, the micro-spraying belts are used for seedling stage irrigation, primary irrigation is carried out in 7 months and 2 days, irrigation is carried out for 1 time every day from 7 months and 2 days to 8 months and 5 days,the irrigation time is 40 minutes each time, and the irrigation quantity is 67m³/hm²Irrigating for 1 time every 2 days from 8 months and 6 days to 10 months and 1 day, wherein the irrigation time is 60 minutes, and the irrigation quantity is 100m³/hm²Removing the surface micro-spraying belt in 2 days after 10 months, starting the underground drip irrigation system, irrigating once every 7 days, wherein the irrigation time is 8 hours/time, and the irrigation quantity per time is 600m³/hm²；

(6) Harvesting 4 times in 5-month-12 days, 6-month-24 days, 8-month-2 days and 9-month-20 days in 2020, drying and weighing after harvesting, applying 10 kg/mu of monoammonium phosphate with irrigation after each harvest, and measuring yield to 15800kg/hm of alfalfa hay in 2020²。

Comparative example:

(1) selecting Xindong No. 22 wheat as a previous crop, sowing for 9, 10 and 2018, and applying 30 kg/mu of diammonium phosphate before sowing;

(2) harvesting winter wheat in 2019 in 20 months in 6 months, wherein the stubble height is 25cm-30cm, and underground drip irrigation devices are arranged on wheat stubbles in 24 months in 6 months, the buried depth of drip irrigation belts is 20cm, the drip irrigation belts are of an embedded patch type, and the distance between the drip irrigation belts is 45 cm;

(3) adopting a drill seeder to sow the alfalfa, wherein the row spacing is 20cm, the sowing depth is 1-2cm, and the sowing quantity is 22.5 kg/hm²The time is 6 months and 26 days; irrigating for 1 time every 3 days from 1 day in 7 months to 31 days in 7 months for 12h each time;

(4) only alfalfa within 5cm beside the drip irrigation zone can emerge, and because of the overhigh ground surface temperature, alfalfa seedlings die gradually after being sown for 15-20 days, the survival rate of the seedlings is 30% of the emergence of seedlings, and the production significance is not realized.

Claims (1)

1. A planting method for protecting seedlings and saving water of alfalfa in a windy and sandy land is characterized by being implemented by sequentially adopting the following operation steps:

step 1, an underground drip irrigation tape is distributed by adopting an underground drip irrigation pipe distributor, the buried depth of the drip irrigation tape is 20cm, the drip irrigation tape is of an internal patch type, the distance between drippers is 20-40cm, the flow rate of the drippers is 1.5-3.0l/h, the distance between the drip irrigation tapes is 60-75cm, and after the distribution of the drip irrigation tape is finished, buried branch pipes, dry pipes and various connecting pieces are installed for later use;

step 2, planting winter wheat, performing field management according to a drip irrigation wheat planting rule, and harvesting stubble remaining height of 20-30 cm;

step 3, adopting a drill seeder to sow the alfalfa in a no-tillage way, wherein the row spacing is 15cm, the sowing depth is 1-2cm, and the sowing quantity of the alfalfa is 15-30 kg/hm²；

Step 4, laying micro-spraying belts on the well-sowed alfalfa ground, wherein the micro-spraying belts are communicated with the buried branch pipes and the trunk pipes in the step 1, the spacing between the micro-spraying belts is 5-6m, the micro-spraying belts are used for seedling stage irrigation, and the irrigation amount is 75-150m³/hm²The irrigation time is 30-60 minutes, and the rotation irrigation period is adjusted according to the weather conditions such as air temperature, rainfall and the like;

step 5, after the alfalfa grows for 90 days, removing the micro-spraying belt, cutting, irrigating for 1 time every 7-10 days by using an underground drip irrigation device, wherein the irrigation amount is 600-³/hm²。