Is it ok to plant upland rice in the summer from solstice to northern Japan?

During the summer solstice, upland rice can be planted in the north.

Planting upland rice can be divided into spring sowing and summer sowing. Spring sowing can be carried out from mid-April to mid-May, and mid-May is the best. Summer sowing should be before June 15, and the earlier the better.

Early rice is suitable for direct seeding, and there are also rice transplanting in China. This paper mainly introduces direct seeding cultivation.

1. Fine soil preparation is beneficial to the whole seedling, the whole seedling and soil water conservation, and the soil fragments are required to be flat. The main purpose of soil tillage is deep ploughing, soil breaking, moisture conservation and weeding, and the suitable depth is 18 ~ 20cm. The time and method of soil preparation vary with region, climate, soil, farming season and previous crops. There are many weeds in the ripe soil, so it is not advisable to plow and prepare the soil too early to avoid breeding weeds. Newly reclaimed land can be ploughed and then sown.

There are two kinds of upland rice in the north: spring sowing and summer sowing. When sowing in spring, prepare the soil after the harvest of autumn crops, first clean up the stubble with shallow tillage, and then combine with fertilization for deep tillage. Summer sowing is usually sown after potato, barley, wheat and other crops are harvested. At that time, the temperature was high and the evaporation was large, so soil preparation and moisture conservation were particularly important. After harvest, fertilization combined with ploughing, sowing and suppression can keep soil moisture and be beneficial to seedling emergence.

South 1 year over-mature area, rape, barley, wheat, sweet potato (autumn potato or winter potato), potato, etc. It is the top crop of early rice direct seeding, and should be sown in time after harvesting. Slope land in hilly and mountainous areas should be prepared according to contour lines and made into horizontal trapezoidal flat beds to facilitate soil and water conservation. In the intercropping area between grain forests, deep ploughing should be carried out between saplings, combined with fertilization, ground breaking and leveling before sowing.

2. Safe sowing of early rice includes: drying seeds, soaking seeds, disinfection, accelerating germination, sowing, covering soil (suppression) and so on. Sowing upland rice is beneficial to seedling emergence and sufficient seedlings.

(1) The drying, seed selection, seed soaking and seed disinfection are the same as those of ordinary paddy field transplanting. However, the seeds of upland rice can be soaked (that is, the water absorption is more than 60% of its seed weight). Generally, seeds are soaked for 2-3 days, 3-4 days in early season and about 2 days in middle and late stage. Pay attention to changing water and breathing.

(2) Accelerating germination and sowing in the north can generally germinate 4 days earlier, ear 3 days earlier and mature 5 days earlier. Therefore, under suitable conditions, it is better to accelerate germination and sow. However, if the soil moisture is insufficient, it is not suitable to accelerate germination, so as to avoid dry germination, and the seeds can only be soaked until the glume is white.

(3) Early rice seed dressing with chemicals is often harmed by underground pests at seedling stage, resulting in lack of seedlings and broken ridges, which affects yield. The main pests are white grubs, white grubs, needle worms and so on. Among them, grubs are the most common, and seeds should be dressed with chemicals before sowing. Before mixing drugs (usually carbofuran), spread the seeds that have absorbed enough water and dry them until the glume is white.

(4) There are three sowing methods for upland rice: drilling, sowing and on-demand. Drill sowing is the most widely used, and it can be divided into wide sowing and narrow sowing because of different seeders. Machine sowing, small row spacing and narrow sowing width. Artificial furrow sowing with large row spacing and wide sowing width. Row spacing is 25 ~ 30 cm. It can also be planted in holes, with wide rows and narrow plants, with row spacing of 30 cm and plant spacing of 10 ~ 15 cm. The sowing quality of upland rice should be strictly guaranteed, because it is related to whether the whole seedling can be produced, and the growth uniformity in the later stage will affect the yield.

(1) The sowing date varies with climatic conditions and stubble. Generally, sowing begins when the soil temperature reaches above 65438 02℃. Sowing began from late April to early May in Northeast China, mid-April in North China, early April in Yangtze River Basin and mid-March in South China. In the areas lacking irrigation conditions, the sowing date of early rice should be determined mainly according to the rainy season, that is, sowing at the beginning of the rainy season to meet the water demand in the growing period. Upland rice is not suitable for autumn planting in dry land without irrigation conditions. If there are conditions, such as early watering, heading date 1 times irrigation, autumn sowing can achieve high and stable yield. Sowing should not be too late, the sooner the better. When sowing early rice after the harvest of wheat, rape and other crops in the previous summer, due to the tight season, we should hurry and sow early. If sowing is late, the yield will be obviously reduced or even no fruit will be produced. Experience from all over the world shows that timely early sowing prolongs the vegetative growth period, enables rice plants to accumulate more nutrients, and is conducive to increasing panicle grains and obtaining high yield. If upland rice is interplanted before the previous crop is harvested, it should be sown 2 ~ 3 weeks before the harvest, which is premature, takes a long time to grow and makes the seedlings grow poorly.

(2) The sowing amount should be determined according to the tillering ability and germination rate of varieties, and at the same time, attention should be paid to the fatness of the land and whether there are irrigation conditions. If the soil is fertile and the soil moisture is maintained well, it is beneficial to the tillering of upland rice in rainy season, and the sowing amount can be smaller. Generally speaking, spring sowing is 45-90kg per hectare, and summer sowing is 90- 105kg per hectare.

(3) Sowing methods There are many sowing methods, which are beneficial to intertillage weeding. Suppression after sowing in the north is an important link to protect soil moisture and seedlings; Because there is much rain in the south, you can cover the soil after sowing. The more orderly the growth of early rice, the higher the yield. The most important thing that affects the growth uniformity is the uniformity of rice seedlings distribution in the ridge, and it is necessary to ensure uniform grain dropping when sowing. The thickness of soil cover also has a great influence on the emergence, which directly affects the germination rate and emergence uniformity of early rice. If the soil cover is too shallow, the surface water will evaporate quickly in case of drought, so it is difficult to meet the water required by the seeds and it is impossible to germinate. In case of drought after rain, the germinated embryo will grow too fast, consume seed nutrients, weaken the ability of bud sheath to be unearthed, and even make the leaves scatter in the soil, resulting in slow emergence, low emergence rate and underdeveloped root system. The thickness of covering soil should be determined according to soil texture, season and moisture. Generally, loam is 3 ~ 4 cm, sandy soil and soil can be covered deeply when dry, and clay and soil can be covered shallowly when wet. Spring sowing in the south can be shallow, about 3 cm, and summer sowing should be slightly deeper.