High-yielding cultivation techniques of semi-arid rice

① sets up ridges for winter paddy fields to plough in time after rice harvest, rake flat fields, build high ridges, and store water for the winter. Generally no longer ploughing and harrowing after the beginning of spring, but fields with soil consolidation and weeds should be ploughed and raked once in the first half of the month. Ridging is carried out twice, the first is carried out 5-7 days before planting, and the thick ridges are made by pulling the rope to make rough ridges (deep feet, mud fields can be advanced to 7-10 days before planting), which should not be carried out prematurely, lest the ridge surface be exposed for a long time and easy to breed weeds. the second time, 2-3 days before planting, further raise the ridge (box) surface according to the quality requirements, straighten out the trench, arrange and take shape. On the other hand, after the small spring harvest, the winter field was dry-ploughed for several days, and the water pool field was released 3-4 days before planting, and the soil was ridged and formed once after soaking.

The ridging specifications are divided into box type and cymbal type. It depends on the variety, the type of field and the mode of utilization. Chamber type: generally, the width of the box is 60 cm 80 cm, the width of the groove is 33 cm 40 cm, and the depth of the groove is 27 cm 33 cm. General ridge width is 270cm, ditch width is 33cm, ditch depth is 27cm. The big fat field and the 233mm field enlarge the ridge properly and the width of the furrow surface. When making ridges, the field should maintain a water layer of 6 cm to 8 cm. The ploughed mud should be placed gently in turn, do not disturb the soil layer, do not press, do not wipe the ridge surface. The top of the ridge is slightly tiled or flat-topped. After transplanting, the ditch was cleared and ridges were arranged for 1 and 2 times, and the ridges were not removed after rice harvest. Slightly clear ditches and ridges, continue to use in winter to achieve sustainable no-tillage.

The amount of fertilizer applied in semi-dry cultivation of ② is the same as that of flat cropping fields, and its fertilizer application method is generally re-applying base fertilizer and early topdressing (nitrogen fertilizer is applied at one time, the bottom fertilizer accounts for 7080% of the total fertilizer, and topdressing accounts for 2030% of the total fertilizer). Mature fertilizer, ammonium bicarbonate and ammonia water are evenly spread into the whole field before the first ridge, and urea and available phosphorus and potassium fertilizer are spread on the level of the head road before the second ridge. Topdressing is applied within 7-10 days after transplanting. For varieties with long growth period, medium and small seedlings are directly planted in the field, and topdressing should be applied to the seedlings about 20 days after planting.

③ transplanting seedlings according to different types of fields to determine the types of seedlings, cold, shady, rotten, rice fields, often easy to "sit", it is best to plant 7-9-leaf-old seedlings. (strong seedlings with many tillers), in general winter paddy fields, it is appropriate to plant 3.5-leaf medium-leaf seedlings or 2-leaf seedlings. Four or six rows are planted on each ridge of the box. The seedlings must be planted slightly below the water level on both sides of the ridge, one row for each. The row spacing is generally 16-20 cm, and the hole spacing is 10-13 cm: double plants per hole for small seedlings, 6-8 tillers per hole for hybrid rice with many tillers and conventional medium rice, 16-30 thousand holes per mu (depending on soil types and regional ecological characteristics, Yunnan is more, Sichuan is less), 12-180000 basic seedlings (stem tillers).