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建昌县近几年连续干旱,1975～1980年平均年降水量仅为583.2毫米,而且多半集中在第二季度后期和第三季度。建昌地区从4月1日至15日,这一时期失墒严重。据测定,10厘米的表土,含水量每10天减少2.5％。由此可见,抓住墒情,适时播种是保苗的关键。用机械播种能缩短播期,1台播种机播种相当于30～50付犁杖,效率高,能保证把地种在火候上,有利于抢墒保苗。 使用机械还能作到掏墒或开墒下种。掏墒播种,利用芯铧式开沟器开沟,其特点是开出的苗床较宽,使干土大部分分向两侧,坐土基本是湿土。如春旱严重,表土干旱
Jianchang continuous drought in recent years, from 1975 to 1980, the average annual rainfall of only 583.2 mm, and mostly concentrated in the second quarter and the third quarter. Jianchang area from April 1 to 15, this period of loss of moisture is serious. It is determined that 10 cm of topsoil, water content decreased by 2.5% every 10 days. Thus, to grasp the moisture content, timely sowing is the key to seedlings. Sowing with mechanical sowing can shorten the sowing time, a sowing machine is equivalent to 30 ~ 50 sowing poles, high efficiency, to ensure that the ground in the heat, is conducive to grab moisture seedlings. The use of machinery can also be done digging moisture or open moisture under the species. Dig soil moisture sowing, the use of core-type opener ditching, which is characterized by a wide seedbed out, so that most of dry soil points to both sides, soil is basically wet soil. Such as spring drought, topsoil drought