Cultivation methods for forage and fodder crops
By cutting and treating sweet vernal grass with triazine herbicides, the method addresses the challenges of weed control in perennial grasslands, ensuring continuous land use and high-quality forage production.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SNOW BRAND SEED
- Filing Date
- 2025-12-18
- Publication Date
- 2026-06-30
AI Technical Summary
Existing methods for controlling weeds like sweet vernal grass in perennial grasslands are labor-intensive, disrupt continuous use of the land, require costly machinery, and result in reduced productivity due to low nutritional value and allelopathic effects, posing challenges for dairy and livestock farmers.
A method involving cutting down sweet vernal grass, sowing sorghum, and applying a triazine herbicide to selectively eliminate the weeds, allowing the land to be used as a permanent pasture while maintaining productivity.
This approach effectively controls sweet vernal grass, enables continuous use of the land as a permanent pasture, and produces high-quality forage with controlled nitrate levels, reducing costs and increasing productivity.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a method for cultivating forage and feed crops, particularly a method for cultivating forage and feed crops involving halogeton weed control.
Background Art
[0002] In dairy and livestock farming that raises herbivores, roughage is the main source of nutrition. Especially for ruminants with a rumen (the first stomach), roughage with a high crude fiber content is not only a source of nutrition but also an essential feed for stabilizing digestive functions physiologically. Although it is estimated that 78% of the roughage used in Japan is domestically produced (in fiscal year 2022), the Ministry of Agriculture, Forestry and Fisheries has set a goal of achieving 100% domestic self-sufficiency in roughage by fiscal year 2030 due to the high prices of imported feed and the impact of improving self-sufficiency. Especially from the perspective of economic efficiency, it is important to maintain and utilize the productivity of permanent forage grasslands such as timothy and orchard grass in order to increase productivity per unit area. To obtain roughage, there are methods such as cultivating annual grasses as feed crops, such as feed corn and feed wheat, and cultivating perennial forages such as timothy, orchard grass, and clover to cultivate forage as a permanent grassland. Cultivating annual grasses requires costs such as tillage work fees before sowing, seed costs, and sowing work fees. On the other hand, if perennial forages can be cultivated to form a permanent grassland, sowing and tillage work will be unnecessary, so management can be labor-saving. Also, in a permanent grassland, since the soil is compacted the year after tillage, it is difficult for soil to mix into the harvested forage, so high-quality roughage can be obtained. Because of these advantages, especially in Hokkaido and the Tohoku region, the area of permanent grasslands is larger than the area of annual feed crop cultivation.
[0003] In recent years, weeds such as sweet vernal grass and broadleaf plantain have been invading these perennial grasslands, posing a problem. Because these weeds have low yields and low nutritional value as fodder, their invasion and spread in grasslands significantly reduces productivity per unit area (Non-Patent Literature 1). In particular, mature sweet vernal grass plants suppress the sprouting and growth of pasture grasses after grassland renewal due to their allelopathic effects, thus reducing pasture productivity. Furthermore, because they produce a large amount of seeds, they easily invade pastures, and once they invade, control is difficult. Furthermore, sweet vernal grass poses a problem due to its high coumarin content. When coumarin is used as a substrate for silage, the metabolic action of mold produces dicumarol, which has scurvy, making it unsuitable for feeding to livestock. In addition, feeding large amounts to dairy cows may alter the flavor of their milk. For these reasons, contaminated pasture grass may become unusable.
[0004] One method for controlling sweet vernal grass that has invaded perennial grasslands is to apply a non-selective herbicide (Non-Patent Literature 2). However, with this method, after the sweet vernal grass dies, tilling the soil will cause buried seeds to germinate, requiring herbicide application again. This process will result in no harvest from the field for at least one year. As a method of controlling pests while obtaining crops, methods such as cultivating sugar beets and treating them with herbicides (cretozyme) or cultivating autumn-sown wheat and treating them with herbicides (a mixture of indanophan and diflufenican) are known (Non-Patent Literature 2). However, even in these cases, a problem for dairy and livestock farmers is that there is a period of more than one year during which they cannot obtain pasture or fodder crops. Furthermore, it is difficult for dairy and livestock farmers who do not own sugar beet or wheat planting and harvesting machines to implement these methods. One known method of controlling weeds while cultivating forage crops is to plant forage corn and treat it with herbicide (atrazine) (Non-Patent Literature 2). However, this method has the problem that forage corn cannot be planted unless the field conditions are such that there is little slope and good drainage. Furthermore, it cannot be implemented unless there is a machinery system in place to till the field, sow seeds, and harvest shredded silage. In addition, even if the field is sown as pasture after harvesting the forage corn, there is the problem that a sufficient yield of first-cut grass cannot be obtained. Moreover, all of these methods require tilling the soil, so it is not possible to maintain perpetual grassland. Furthermore, the tilling of the field and sowing grass (grassland renewal work) costs 50,000 to 90,000 yen per 10a, making implementation difficult.
[0005] On the other hand, sorghum is a grass crop native to Africa that is highly productive under high-temperature summer conditions. It has many useful characteristics, including excellent lodging resistance. In particular, among sorghum varieties, Sudangrass has many useful characteristics, such as its slender stems that allow for easy water regulation and its vigorous regeneration. However, it has poor low-temperature germination ability, requiring an average temperature of 15°C or higher for sowing. Low temperatures slow growth, and if weeds or other plants are growing nearby, it will lose out to competition, resulting in a lower yield. For this reason, tilling the soil before sowing is essential, and cultivation methods such as sowing in perennial grasslands are not practiced. Furthermore, the feed components of sorghum varieties tend to change depending on the growth stage at harvesting, and a particular drawback when used as feed is that the nitrate nitrogen content in the harvested product can be high (Non-Patent Documents 3 and 4). Since nitrate nitrogen levels also change significantly with fertilization, sufficient management techniques are necessary when using sorghum as feed. For these reasons, although techniques for no-till cultivation of Sudangrass have been developed in western Japan (Non-Patent Literature 5), these cultivation methods involve completely killing the pre-grass with non-selective herbicides and then spraying bentazon liquid on the weeds that emerge later. No method has been developed that allows cultivation while maintaining the pre-grassland. [Prior art documents] [Non-patent literature]
[0006] [Non-Patent Document 1] Materials from the 2018 (Heisei 29) Hokkaido Self-Sufficiency Feed Improvement Council Seminar (P7; 6th session) [Non-Patent Document 2] 2018 Hokkaido Guidance Reference Materials: "Growth Characteristics and Reduction Measures for the Difficult-to-Control Weed 'Sweet Greens' in Grasslands" [Non-Patent Document 3] 1997 Aichi Agricultural Research Institute Report 29 "Trends in Nitrate Nitrogen in Summer Forage Crops (Millet and Sudangrass)" [Non-Patent Document 4] Reduced nitrate nitrogen concentration in Sudan grass through variety selection (National Agriculture and Food Research Organization) [Non-Patent Document 5] 2024 "Standard Operating Procedures for No-Till Cultivation Techniques of Sudangrass (Website Version)" National Agriculture and Food Research Organization [Overview of the Initiative] [Problems that the invention aims to solve]
[0007] The object of the present invention is to provide a method for cultivating perennial pasture and fodder crops by weeding sweet vernal grass with simple operations. [Means for solving the problem]
[0008] The inventors of the present invention conducted various studies to solve the aforementioned problems and discovered that by cutting down sweet vernal grass growing in a grassland, then sowing sorghum and applying a triazine-based herbicide, sweet vernal grass can be selectively eliminated, sorghum can be harvested efficiently, and the area can subsequently be used as a permanent pasture. Thus, the inventors completed the present invention.
[0009] In other words, the present invention provides the following inventions [1] to
[12] . [1] A method for cultivating pasture grasses and fodder crops, characterized by cutting down sweet vernal grass growing in a grassland, sowing sorghum, and then applying a triazine-based herbicide. [2] The method for cultivating pasture grasses and fodder crops as described in [1], wherein the triazine herbicide is selected from chlorotriazines and methylthiotriazines. [3] A method for cultivating pasture and fodder crops according to [1] or [2], wherein the triazine herbicide is selected from simazine, atrazine, cyanazine, ametrin, dimethametryn, simetryn, and promethrin. [4] A method for cultivating pasture and fodder crops as described in any of [1] to [3], wherein the sorghum is Sudanese sorghum or Sudangrass. [5] The method for cultivating pasture and fodder crops described in [4], where sorghum is Sudangrass. [6] A method of cultivating pasture grasses and fodder crops as described in any of [1] to [5], wherein the harvesting period for sweet vernal grass is after the sweet vernal grass has headed. [7] A method of cultivating pasture and fodder crops as described in any of [1] to [6], wherein sorghum is sown in rows. [8] A method for cultivating pasture and fodder crops as described in any of [1] to [7], wherein the sowing rate of sorghum is 7 kg / 10a or less. [9] A method for cultivating pasture and fodder crops as described in any of [1] to [8], wherein the nitrogen content in the soil at the time of sowing sorghum is 6 kg / 10a or less in terms of chemical fertilizer application.
[10] A method for cultivating pasture grasses and fodder crops as described in any of [1] to [9], wherein the cutting height at the time of harvesting sorghum is 15 cm or more.
[11] A method for cultivating pasture and fodder crops as described in any of [1] to
[10] , wherein the nitrate concentration of harvested sorghum is 1500 ppm or less.
[12] A method of cultivating pasture grasses and fodder crops as described in any of [1] to
[11] , wherein pasture grass seeds other than sweet vernal grass are sowed after the harvest of sorghum. [Effects of the Invention]
[0010] According to the present invention, by treating sorghum with a triazine herbicide during cultivation, it is possible to control Halogaya that has invaded permanent grasslands, and at the same time, harvest the grown sorghum as roughage. In addition, since the permanent grassland is not plowed, it can be continuously used as a permanent grassland, and the feed value of the grass silage obtained from it every year is expected to be 35,000 yen / 10a. The costs are low, including the cost of sudangrass seeds (6,000 yen to 10,500 yen / 10a), fertilizer and herbicide costs (1,000 yen / 10a), and the cost of overseeding seeds (5,000 yen / 10a).
Mode for Carrying Out the Invention
[0011] The terms used in this specification are used in the meanings commonly used in the art, unless otherwise specified.
[0012] The present invention is a method for cultivating forage and feed crops by controlling Halogaya, a weed that has invaded permanent grasslands. One aspect thereof is a method for cultivating forage and feed crops, characterized by sowing sorghum after mowing Halogaya growing in the grassland and performing triazine herbicide treatment.
[0013] As described above, Halogaya is a weed known to invade permanent grasslands. Since its yield is low and its nutritional value as feed is low, when it invades and spreads in the grassland, the productivity per unit area significantly decreases. In the present invention, first, Halogaya growing in the grassland is mowed. Gramineous plants, including Halogaya, accumulate carbohydrates in their stems and leaves before heading, so they have high regenerative ability when mowed at this time. Therefore, it is preferable to mow Halogaya after it has headed. The mowing can be done at any time after heading, but the period from heading to fruiting is preferred, the period from heading to milk ripening is more preferred, and the period from heading to flowering is even more preferred.
[0014] After harvesting the alfalfa, sorghum is sown. Sorghum is not particularly limited, but Sudan-type sorghum or Sudan grass is preferred because it is easy to adjust the moisture after harvesting and has high regenerative power, and Sudan grass is more preferred.
[0015] The seeding method of sorghum is not particularly limited, but drilling is preferred, and more preferably drilling using a furrow-making type simple grassland renewal machine. Examples of the drill include, but are not limited to, Seedmatic, Great Plains, and Seedmaster. The seeding rate of sorghum is not particularly limited, but it is preferably 7 kg / 10a or less in order to avoid competition. The fertilizer applied when sowing sorghum is not particularly limited, but in order to prevent the nitrate nitrogen concentration in the harvested product from being too high, it is desirable that the nitrogen component in the soil at the time of sowing sorghum is 6 kg / 10a or less in terms of chemical fertilizer application. The timing of fertilizer application is not particularly limited as long as it is after harvesting the alfalfa, but after sowing sorghum is preferred. The seeding period of sorghum is not particularly limited as long as the ground temperature is 15°C or higher, but preferably from the middle to late June to the first ten days of July.
[0016] After sowing sorghum, a triazine herbicide treatment is carried out. By carrying out the triazine herbicide treatment, the alfalfa is weeded, and the sorghum selectively germinates and grows. Examples of the triazine herbicide include herbicides selected from chlorotriazines and methylthiotriazines, and specifically, herbicides selected from simazine, atrazine, cyanazine, ametryn, dimetametryn, simetryn, and prometryn are preferred.
[0017] Due to the triazine herbicide treatment, the alfalfa is weeded, and the sorghum selectively germinates and grows, so the grown sorghum can be harvested as a forage or feed crop. When harvesting sorghum, it is preferable to cut it at a height of 15 cm or more to reduce the nitrate nitrogen concentration in the harvested material and to avoid mixing it with vegetation that remains even after herbicide treatment. This allows for the harvesting of sorghum with a nitrate concentration of 1500 ppm or less for use as feed.
[0018] After harvesting sorghum, overseeding with forage grass seeds can increase the yield of forage grass from perennial grasslands. There are no particular restrictions on the type of forage grass, but timothy, orchardgrass, festulolium, fescue varieties such as tall fescue and meadow fescue, and ryegrass varieties such as Italian ryegrass are preferred, with timothy being particularly preferred. For sowing methods, simple furrow-type overseeding can be used. It is also preferable to apply fertilizer as needed. There are no particular restrictions on the amount of seed to sow, but 1 to 5 kg / 10a is preferred depending on the existing vegetation, and 2 to 3 kg / 10a is even more preferred. [Examples]
[0019] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.
[0020] (Example 1) In a sweet vernal grass-dominated field (crown cover; Table 1) in Tsukigata-cho, Kabato-gun, Hokkaido, after harvesting the first crop on June 29, the field was not tilled, and on July 3, Sudan grass (variety: Heisudan (Snow Brand Seed Co., Ltd.)) was sown at a rate of 7 kg / 10a using a furrow-type simple renewal machine. The fertilizer applied at this time was 6 kg of nitrogen, 6 kg of potassium, and 6 kg of phosphorus. A Great Plains sowing machine was used, with a row spacing of 18 cm, a sowing depth of 3.5 cm, and a speed of 4 km / hour. On July 16, 45% atrazine (product name 200 ml / 10a of gezaprim flowable was sprayed. On August 16, the grass was cut down to a height of 15 cm from the ground, pre-dried in the field for two days, and then prepared into roll-pack silage. On September 3, the regenerated second cutting was harvested. The obtained Sudan grass was analyzed for nitrate nitrogen using cadmium reduction spectrophotometric analysis with a continuous flow analyzer (BLTEC SWAAT28). Furthermore, on September 13, 2 kg / 10a of timothy grass (variety: Maoi (Snow Brand Seed Co., Ltd.)) was sown. Furthermore, after harvesting the first crop on June 22 of the following year, without tilling, Sudan grass (Snow Brand Seed Co., Ltd.) was sown at a rate of 4 kg / 10a or 6 kg / 10a using a furrow-type simple regeneration machine on June 27. The fertilizer applied at this time was 6 kg of nitrogen, 6 kg of potassium, and 6 kg of phosphorus. On July 12, 200 ml / 10a of 45% atrazine (product name: Gezaprim Flowable) was sprayed. On August 8, the grass was cut down to a height of 15 cm from the ground, and the yield and vegetation of Sudan grass were investigated. The vegetation was investigated using the overhead observation method. The weather conditions that year were severely drought-prone. The obtained Sudan grass was analyzed for nitrate nitrogen using cadmium reduction spectrophotometric analysis with a continuous flow analyzer (BLTEC SWAAT28).
[0021] Table 2 shows the yield of Sudan grass in Example 1. A yield of 3 t / 10a was obtained in the first cutting. Furthermore, the nitrate nitrogen concentration was 1000 ppm or less, making it suitable for use as animal feed. Table 1 also shows the crown cover in Example 1 before the first harvest (June 20), 5 days after harvesting Sudan grass (August 21), and 61 days after sowing timothy grass (November 15). Compared to before the first harvest, the proportion of sweet vernal grass has decreased, indicating an improvement in vegetation. Furthermore, the results of the vegetation survey conducted the following year are shown in Table 3. The canopy cover of sweet vernal grass had further decreased to 5%, while the canopy cover of pasture grass had improved from the initial 30% to 60%. Furthermore, the results of the Sudan grass yield survey conducted the following year are shown in Table 4. In all planting rates, a fresh grass yield of 300 kg / 10a or more was obtained even under drought conditions, and the nitrate nitrogen concentration was 1000 ppm or less, making it suitable for use as fodder.
[0022] [Table 1]
[0023] [Table 2]
[0024] [Table 3]
[0025] [Table 4]
[0026] (Example 2) Optimizing the timing of herbicide application In Naganuma-cho, Yubari-gun, Hokkaido, 200 ml / 10a of 45% atrazine (product name: Gezaprim Flowable) was sprayed onto sweet vernal grass on May 8th (before heading), May 15th (at heading), and June 19th (after heading, 2 weeks after harvesting). Survival rates were investigated 1 month and 2 months after spraying.
[0027] Table 5 shows the survival rates in Example 2. The survival rate was lowest and regrowth was minimal when the treatment was applied two weeks after harvesting. This indicates that applying the treatment after harvesting, following heading of sweet vernal grass, is effective.
[0028] [Table 5]
[0029] (Example 3) Proof that sorghum species can also be sorghum-type sorghum. In a timothy-dominated grassland in Naganuma-cho, Yubari-gun, Hokkaido, after harvesting the first crop on June 19th, sorghum (variety: Hybrid Sorghum (Snow Brand Seed Co., Ltd.)) was sown at a rate of 2 kg / 10a on June 24th using a furrow-type simple renewal machine (overseeder (Bred)) without tilling. The fertilizer application amounts at this time were 1.25 kg of nitrogen, 0.48 kg of potassium, and 1.73 kg of phosphorus, or 3.75 kg of nitrogen, 1.44 kg of potassium, and 5.19 kg of phosphorus. The amounts used were 7.5 kg of nitrogen, 2.89 kg of potassium, and 10.39 kg of phosphorus. The seeding machine was set to a row spacing of 15 cm, a seeding depth of 0.5-1 cm, and a speed of 3-4 km / hour. Harvesting took place on August 21, and the yield was investigated. The weather conditions that year were severely drought-prone. The obtained Sudan grass was analyzed for nitrate nitrogen using cadmium reduction spectrophotometric analysis with a continuous flow analyzer (BLTEC SWAAT28).
[0030] Table 6 shows the sorghum yield in Example 3. In all fertilization rates, a fresh grass yield of 100-1,000 kg / 10a was obtained under drought conditions, and the nitrate nitrogen concentration was 1,000 ppm or less, making it suitable for use as animal feed.
[0031] [Table 6]
Claims
1. A method for cultivating pasture grasses and fodder crops, characterized by cutting down sweet vernal grass growing in a grassland, sowing sorghum, and then applying a triazine-based herbicide.
2. The method for cultivating pasture grasses and forage crops according to claim 1, wherein the triazine herbicide is selected from chlorotriazines and methylthiotriazines.
3. The method for cultivating pasture grasses and fodder crops according to claim 1, wherein the triazine herbicide is selected from simazine, atrazine, cyanazine, ametrin, dimethametryn, simetryn, and promethrin.
4. The method for cultivating pasture grasses and fodder crops according to claim 1, wherein the sorghum is Sudanese sorghum or Sudangrass.
5. The method for cultivating pasture grasses and fodder crops according to claim 4, wherein the sorghum species is Sudangrass.
6. The method for cultivating pasture grasses and fodder crops according to claim 1, wherein the harvesting time for sweet vernal grass is after the sweet vernal grass has headed.
7. The method for cultivating pasture grasses and forage crops according to claim 1, wherein sorghum species are sown in rows.
8. The method for cultivating pasture grasses and forage crops according to claim 1, wherein the amount of sorghum seeds sown is 7 kg / 10a or less.
9. The method for cultivating pasture grasses and forage crops according to claim 1, wherein the nitrogen content in the soil at the time of sowing sorghum is 6 kg / 10a or less in terms of chemical fertilizer application.
10. The method for cultivating pasture grasses and forage crops according to claim 1, wherein the cutting height at the time of harvesting sorghum is 15 cm or more.
11. The method for cultivating pasture grasses and forage crops according to claim 10, wherein the nitrate concentration of harvested sorghum is 1500 ppm or less.
12. The method for cultivating pasture and fodder crops according to claim 10, wherein pasture grass seeds other than sweet vernal grass are sowed after the harvest of sorghum.