SU1554818A1 - Method of cultivating corn for grain - Google Patents

Abstract

The invention relates to agriculture and can be used in the cultivation of corn for grain on irrigated land. In order to obtain high sustainable grain yields in regions with frequent air droughts occurring during the flowering period with a decrease in water flow, during the period from sowing to the appearance of 7–8 leaves, soil moisture is maintained at a critical level, then four irrigations are carried out. phases by the beginning of the occurrence of 7-8 leaves, 11-12 leaves before flowering from the time of occurrence of panicles and before flowering cobs from the time of occurrence of yarn norms calculated by the formula P _I = ^V. HB ^_I. H _{I + 1} ((Ω _{I + 1} + Δ _I ): 100) -Ω _I -ΔΩ _{I + 1} + EI _{I , I + 1} where P _I is the desired irrigation rate, m ³ / ha, the next I-th watering

I - irrigation number = 1,2,3,4, НР _{I + 1} - average least water-holding capacity of the soil layer, occupied by roots at the end of the irrigation interval, m ³ / t

V is the volume mass of the soil, t / ha ^. m

@ _I - moisture reserve in the root zone at the time of the start of irrigation, m ³ / ha

Δ @ _{I + 1} - increment of moisture reserve due to root growth during the irrigation period, m ³ / ha

H _{I + 1} - the depth of the soil layer under corrosion at the end of the irrigation period, m

@ _{I + 1} - critical humidity of sowing at the time of the next (I + 1) -th watering,% of HB, VP _{I, I + 1} - water consumption of the crop for the period from the I-th watering to ( _{I + 1} ) -th watering , m ³ / ha

Δ _I - the threshold value of the pre-irrigation humidity relative to the critical humidity,% of HB, is set, and the values of Δ _{I are} set within -10≤Δ ₁ ≤-5

-10≤Δ ₂ ≤-5

5≤Δ ₃ ≤ ₁₀ , Δ * 980, and the fourth and subsequent irrigations are carried out with permissible norms ensuring maximum transpiration. In addition, with the onset of extremely dry weather in the early periods of crop development, but not earlier than the phase of 3 leaves, allow a short-term excess of the critical humidity over soil moisture by 10-15%. 2 hp f-ly, 1 tab.

Description

The invention relates to agriculture and can be used in the cultivation of corn for grain on irrigated land.

The purpose of the invention is to obtain high sustainable grain yields in regions with frequent air droughts occurring during the flowering period, while reducing water consumption.

Figure 1 presents a graph of the growth of the critical humidity of sowing corn in the phase of 3-5 leaves, depending on the soil moisture; Fig. 2 is a graph of the dynamics of soil moisture with a rooted layer (a), critical moisture of crops (b), water consumption (c), sheet index (d), panicle bloom (e) with the known (1) and proposed (2) the method of growing corn for grain; FIG. 3 shows the dependence of the critical moisture content of two corn crops grown at different levels of soil moisture: right 1 - at a humidity of 0.8 from HB, right m 2 - at a humidity of 0.6 from HB.

According to the proposed method of growing corn for grain, irrigation is carried out in compliance with a predetermined soil regime, while in the period from sowing to the appearance of 7-8 leaves, the soil moisture is maintained at a critical level and allows for a short-term decrease by 10-15% below the critical conditions of water deficiency) due to the drought tolerance of the culture and the absence of the need for its tillering. A deeper deficit leads to a significant upholding of growth and a decrease in the photosynthetic potential in subsequent phases of development. This is one of the differences of the proposed method from the known. Before the beginning of the III-IV stages of organogenesis (laying of the generative organs, phase 7-8 leaves), irrigation is carried out by the norm, which increases soil moisture in the root zone to such a level that at the beginning of the next irrigation, dated to the period of stamen formation and pollen formation (orogenesis , phase, 11–12 leaves) soil moisture decreased to a critical level. The calculation of irrigation norms that meet the proposed method of cultivation is found by the equation

wi, + iwit- Bnu-t L + ni1

v VHBH

 Wy + D 100

where Wt is the amount of plug in the root layer at the time of the start of watering (pre-irrigation moisture reserve), & ± is the increment of moisture reserve

due to root growth in the interpolation period, m / ha;

VP. , - total water consumption - V l

sowing for interfolv3 / non-period, m / ha,

five

0

five

0

At, H

HB H

W

the expected difference in soil moisture (W) and critical sowing moisture at the end of the irrigation interval (W) is set according to the proposed method,% of HB; D Wf - WtKa; Ws - soil moisture,% of HB, depth of soil that is being consumed at the end of the inter-irrigation period, m, the average value of the lowest moisture capacity of the root-eroding soil layer at the end of the inter-irrigation period, the value of the critical sowing moisture at the end of the inter-irrigation interval,% of

pv;

irrigation rate at time t,

m3 /

ha

or P „V

HB, x

- "

. , H / Ј + ysg h „AP

x V loo} - w. - AWV

five

0

five

0

five

In phase 11–12, leaves are watered at a rate that provides for a decrease in soil moisture by the time the panicle appears to a critical level. The next two irrigations in the phase of sweeping out panicles and the beginning of flowering of the cobs are produced by such permissible standards at which by the end of the inter-irrigation period the soil moisture in the root zone remained 5-10% above the critical level. A higher level of humidity leads to a noticeable decrease in drought resistance and negatively affects the water-air regime of the soil in the root zone, increases the infiltration flow. Further, the level of soil moisture until the end of milky ripeness is maintained in the range providing maximum transpiration. By the end of the grain loading period, the soil moisture is reduced to a level not lower than 40-50% of HB to preserve the ears on the stalks.

The method is carried out as follows. at once.

Iodine critical iodine by the soil of the WK soil is defined as a specific sowing, which means that the moisture content of the soil for the weather data is the lowest, which does not lead to a noticeable decrease in tranppyration and photosynthetic productivity of plants. as an adaptive plant for water pressure.

71l of maize plants are characterized by a high sensitivity of yield dependencies on moisture deficit in the critical period of development, associated with two negative events

but also blt.1 in the in-AIR mode pochp in the root zone, reducing the possible destruction of the structure | . Soil processes, reduction of physical evaporation from the soil, water saving LTO, in its turn, increases the growth of the root system, leads to a change in the plant's UHT plant towards drought tolerance of forms and distortion of the effluent. The strung-up campaign is such that, while creating bachagotnye umopi to dilute the yield of the crop, they strive to preserve the DRY-RESISTANT habit

5 plants, their xeromorphy, formed in the early stages of vegetative growth. This, in turn, makes it possible to increase the soil moisture in the response.

25

thirty

arising under water stress and under-20 stepped periods of plant development leading to a sharp decrease in grain yield. This decrease in fertility or the formation of sterile pollen, cessation of flowering of the panicle before weaving out the yarns or drying of the yarns (mismatch of flowering time of the panicle and the cobs under unfavorable conditions). Spraying and fertilization of female flowers with low fernous pollen or sterile pollen, as well as pollen dry pestle threads lead to grain cutting and lower yields. Yields are greatly influenced by the condition of the period of laying the future panicles and cobs (phase 7-8 leaves), which determines the duration of the flowering of the panicle, the size of the cobs and the number of grains in them. An increase in soil moisture is 10–15% higher than the critical one in the most sensitive periods of reproductive development of plants (7–8 fox35

40

due to the use of small complete norms and those with IMUM, it reduces or completely eliminates the effect of air droughts with the ADMISSIBLE soil cover. The described strategy is expedient in the sense that with the help of the proposed irrigation regime, this maximum Lotosynthetic potential is formed, which is most realized in grain yield. Some decrease in the elevation of the aboveground biomass and leaf area is compensated for by increasing the radiation regime of the lands, increasing the efficiency and continuity of the photosynthetic apparatus of the plants. Thus, a more complete use of elements of mineral nutrition and moisture per unit of production, more uniform use of soil moisture is achieved. At the same time, the irrigation rate is distributed to the vegetative growth, the formation of the photosynthetic potential and the fertilization of reproductive organs and the loading of grain in such a way that the contributions of each part to the yield (according to the degree of influence) are equal. In this case, both in the mathematical and in the biological sense, the irrigation regime turns out to be optimal for a given resource of irrigation flow (for specific soil-climatic conditions of expression).

(11-12 leaves, flowering of the panicle and cobs) ensures the elimination of water pressure and water stress, creates comfortable conditions for laying out a component of the crop structure, leads to the formation of large ears, a large amount of highly fertile pollen, increases the duration of the panicle bloom, reduces the possibility of drying threads. The use of moderate irrigation norms (strictly calculated by water consumption, the level of critical humidity and the depth of the rooted layer) during critical periods provides not only the creation of comfortable conditions for reproductive organogenesis,

25

thirty

20 cultivated periods of plant development 35

40

45

Jq

five

due to the use of small irrigation rates and to those with IMUM, it reduces or completely eliminates the effect of air droughts with the ADMISSIBLE soil cover. The described strategy is expedient in the sense that with the help of the proposed irrigation regime such maximum Lotosynthetic potential is formed, which is most realized in the grain yield. A slight decrease in the elevation of the aboveground biomass and leaf area is compensated for by increasing the radiation regime of crops, increasing the efficiency and continuity of the photosynthetic apparatus of plants. Thereby, a more complete use of the elements of mineral nutrition and moisture per unit of production, more uniform use of soil moisture is achieved. At the same time, the irrigation rate is distributed to the vegetative growth, the formation of the photosynthetic potential and the fertilization of the reproductive organs and the filling of the grain in such a way that the contributions of each part to the value of the yield (according to the degree of influence) are equal. In this case, both in the mathematical and in the meaningful biological sense, the irrigation regime turns out to be optimal for a given resource of irrigation flow (for specific soil and climatic conditions of vyraganiya).

Figure 1 shows the dynamics of changes in the magnitude of the critical moisture content of corn sowing in the 3-5 leaf phase with constant meteorological intensity (constant evaporation) and

different levels of soil moisture. The observed effect of the progressive growth rate of the critical humidity, depending on the magnitude of the soil moisture difference and the critical humidity, indicates the importance of the pre-irrigation role in the formation of drought-resistant habitus and xeromorphism of the leaves. Figure 2 shows the main stages of maize organogenesis, shows the dynamics of soil moisture with the known and proposed methods of cultivation (1a, 2a), the dynamics of the critical humidity of crops (16, 26), the dynamics of water consumption of a crop during the vegetation period, the dynamics of an increase in the area of leaves ( 1 g, 2 g) and the duration of the flowering panicle (1d, 2d) with the known and proposed methods, respectively. Figure 3 shows the dependence of the critical moisture content of two corn crops grown at different levels of maintenance: soil moisture, evaporation.

Example. In the field conditions of the steppe, which is characterized by frequent air droughts (dry winds), occurring during the flowering of maize and leading to a significant decrease in the yield of this crop, experiments were carried out on the effect of various irrigation regimes on the yield formation of corn grain. On the basis of the studies conducted, the curves of the dynamics of the growth of culture and the parameters of the crops, presented in Figures 2 and 3, were constructed.

Thus, for example, curve 16 shows that during the period of pollination and formation of plants (the most stressful for meteorological periods) with a known irrigation regime (sowing 1) plants are in a state of pronounced water stress. This leads to a grain farm, a fine grain, and ultimately reduces yield. On days with high air temperature and low humidity during the period of bloom, folding of the upper leaves was noted, their folding took place, and the ends of the threads of the cobs dried out. The state of depression was also observed later, during the period of grain loading.

Sowing grown by the proposed method (sowing 2), had a manifestation of xeromorphic structure: shortened

stems, smaller leaf size, less recession and yellowing. Sowing 1 had a higher initial growth rate with stems and leaves, but by the phase of 15 leaves a noticeable decrease in the growth rate of the aerial part was observed and prolonged states of depression (overheating of the crop) were recorded in the midday hours, while sowing 2 grown by the proposed method had only weak manifestations as such.

The table presents a comparison of the characteristics and elements of the structure of crops of corn crops with the known and proposed methods.

Taking into account under-consumption by phases, as well as registering the level of critical humidity of sowing and developmental phase, the irrigation regime was maintained in strict relation to the development time in accordance with the scheme: the appearance of 7–8 leaves 350 me / ha, 11–12 leaves 400 m / ha; before panning out 650m / ha; before spitting up the filaments 700 me / ha; in the period of grain loading - three irrigations of 500, 400 and 300 m / ha. At the same time, soil moisture in the root zone is pre-irrigated with varying weights, respectively: 50.55.70.70.75 and 70% of HB; the depth of the main mass of the roots was: 40,55,70, 150 and 170 cm, respectively. It should be noted that the first watering was carried out 3-4 days earlier, i.e. in a phase of 5-7 leaves. The need for watering was caused by a steady increase in the critical humidity of 10% due to the increased intensity of weather conditions.

To create moisture in the root zone, required by a known irrigation scheme, i.e. Maintaining the pre-irrigation humidity at 70 and 80% of HB, it took 4000 m3 of irrigation water, which was distributed in irrigation as follows: 500, 600, 700, 700, 600, 500 and 400 m3 / ha. The increase in consumption is associated with both a somewhat larger culture evaporation and an increase in infiltration.

For calculating irrigated norms and predicting the state of sowing, the ratio proposed by Budagovsky was used, which relates the critical humidity to evaporation — a characteristic of the intensity of meteorological conditions:

u u + u F w wo T o j

where W is the critical moisture value for seeding, the fraction of

nv;

WQ is soil moisture at which growth is slowed down with minimal intensity of weather conditions.

p „- 0);

$ - empirical coefficient,

h

Е0 - evaporation, mm. h (. The coefficient y is not a constant characteristic for a given culture. Its value is related, on the one hand, to the availability of soil moisture to plants, determined by the water-physical properties of the soil, its moisture content and the degree of development of the root system, the other is with the ability of plants to evaporate water, the degree of xeromorphy of leaves, the age of the plant. In this regard, the coefficient) (can be represented as a function of the form:

Y- Y (Ј L, R, wS h-СМЛ cu- w,

where k is the dimensional coefficient

proportionality;

l

c- - the amount accumulated by sowing

, t

temperatures (plant age);

W - the amount of available moisture

(soil characteristics); current soil moisture, (VZ - humidity of the plant);

L - sheet index m2 / m, K- - root penetration depth, or mass;

  empirical coefficients determined for a particular crop and soil type.

Analysis of this expression shows that, with all other conditions being equal, the steepness of the dependence of the critical moisture of crops on the intensity of weather conditions (E0) depends on the characteristics of the absorbing (R) and evaporating (L) parts of the plant. In addition, it turned out that it is advisable to include such a parameter in the empirical ratio for corn sowing as the average value of the ratio of leaf mass to root mass for the period from germination to the current moment as the xeromorphic parameter characterizing the pre-history of sowing (mu / m). Intensification of the coefficients of this ratio rolls high component importance (mL / m), i.e. xeromorphy factor. In this regard, the expression for calculating the critical humidity differs from the corresponding formula for cereal crops.

Presented view dependency

W + o

C7

L -R5 (mz / m) E,

used to analyze and monitor the critical seeding moisture level. At the same time, the maintenance of humidity within (WK, Wy “L) leads to the formation of sowing, not only having a more drought-resistant habit, but also more xeromorphic leaves. The physiological explanation of this phenomenon is that when the pressure of the water factor is observed, an increased content of sugars is observed due to a decrease in the intensity of growth processes in the aerial part. These sugars are redistributed to the root zone and are used to synthesize the structural substance in the root, increasing their mass. At the same time, the presence of a relatively high content of osmotically active substances (sugars) in the leaves for a long time leads to morphological changes in the structure of the leaf, markedly increasing their xeromorphicity.

An analysis of the water consumption dynamics of crops grown according to the known and proposed methods shows that the water consumption of these crops is almost equal, but the crops that have the aerial part that is more developed in the early stages appear to be in periods of droughts and high intensity of meteorological conditions. While planting 2 is experiencing only a slight depression, which does not lead to a sharp decrease in pollen fertility and a decrease in the flowering period of the panicle, the filaments dry out, and the leaves form.

Increasing the soil moisture during the loading period to the level of the maximum possible transpiration allows more efficient use of the created photosynthetic potential for grain loading. In addition, a better radiation regime in sowing 2 and a smaller aboveground biomass, which distracts a smaller part of photosynthetics to the processes of maintenance of vital activity, also lead to greater efficiency in the use of photo-synthetic potential, the use of water resources, and mineral nutrition.

The critical sowing moisture can be determined using heat balance methods or by measuring temperature gradients in the sowing, as well as by computational methods using dynamic models of agrocenoses.

The required irrigation regime can be carried out by high-capacity sprinkler machines, which allow irrigation with necessary norms for short periods of time.

The use of the proposed method for the cultivation of corn for grain makes it possible to obtain a stable grain harvest of corn in regions with frequent air droughts, an increase in the yield of corn grain in severely arid years, lodging resistance, water use efficiency per unit of production, as well as the possibility of obtaining high yields at water scarcity. Saving irrigation water increases by 10-20%.

Claims (2)

1. A method of cultivating maize for grain, including irrigation in compliance with a predetermined regime of soil moisture, characterized in that in order to obtain high sustainable yields of grain in regions with frequent air droughts occurring during the period of flowering with a decrease in water flow from Sowing before the phase of occurrence of 7-8 leaves soil moisture is maintained at a critical level, then four irrigations are carried out in phases no later than the onset of the appearance of 7-8 leaves, 11-12 leaves, before the beginning of flowering from the time of the appearance of panicle m until the beginning of flowering Cobs from the time of the appearance of the threads, the norms calculated by the formula g five 0 P V HB + VP; ,,,, where Pi. h- -t664L) -w- -flw «« five 0 five 40 45 50 Mr. HB. w. Uw. V, , vp . ( artificial irrigation rate m3 / ha of the next 1st irrigation; irrigation number 1,2,3,4, average least moisture of the soil layer, occupied by the roots by the end of the irrigation interval, m / t; soil bulk, t / ha.m; moisture reserves in the root zone n, 1 point at the start of irrigation, m3 / ha; increment of moisture reserve due to root growth during the irrigation period, m3 / ha; depth of the cornean layer of soil at the end of the inter-irrigation period, m; critical soil moisture at the time of the next (i + 1) -ro irrigation,% of HBJ water consumption of the crop from the 1st irrigation to (i + 1) -ro irrigation, m / ha; set the threshold of pre-irrigation humidity relative to the critical humidity,% of HB, here, the values of L are set in the ranges: -10 ,4, -5; -106De -5; 5th U.,, and the fourth t and the subsequent irrigations are carried out by erosion tolerance, not exceeding the excess surface and depth discharge, by norms that ensure maximum transpiration () and are consistent with traditional irrigation regimes. 2. The method of pop. 1, characterized in that upon the onset of extremely dry weather in the early periods of crop development, but not earlier than the 3 leaf phase, the critical moisture content of the soil is 10–15% higher than the soil moisture and only when the difference is sustained. the norm calculated by the above formula with the value of L, - and,. D, u oja i W Phage. / 4 # c  nift & eefes-E | of i / I one