不同种植密度对寒地水稻浅土层热效应的影响

Planting Density Affects the Thermal Effect in Shallow Soil of Cold Region Rice

为了提高人们对寒地水稻浅土层热效应特征变化的认知度。试验在大田条件下,以‘空育131’为试验材料,设置行株距30×8 cm(D1)、30×10 cm(D2)、30×12 cm(D3)、30×14 cm(D4)、30×16 cm(D5)5个密度水平,分析不同种植密度对浅土层热效应的影响。结果表明,各土层温度在抽穗期达最高值,灌浆后开始下降,且温差缩小,其中以10 cm土层温度稳定性最高。受种植密度影响,高密度处理下土温白天增温快,夜间最低,昼夜温差大,最高日平均温度出现的早,其中D1、D2处理在10 cm、15 cm土温变化上几乎同步。相比之下,各土层Tmax、Tmin出现时间随土层的加深而向后推迟,生育期内Tavg、Tmax、Tmin与气温极显著正相关,而Tmaxmin则随密度的增加有减小的趋势,主要表现在分蘖期和成熟期,且作用效果随密度增加而增大。产量以D2处理最高,表现为9.27 t/hm2,较D1、D5处理增幅13.5%~14.6%。说明适宜密度条件能够实现对浅土层热效应的科学调控,并获得产量的提高。

The objective is to improve people’s awareness of the thermal effect change in shallow soil of rice in cold region.The experiment was carried out in field,and‘Kongyu131’was used as the experimental material Five planting densities were set up,including 30×8 cm(D1),30×10 cm(D2),30×12 cm(D3),30×14 cm(D4)and30×16 cm(D5),respectively.The effects of different planting densities on the thermal effect of shallow soil were analyzed.The results showed that the temperature of all soil layers reached the highest value at heading stage,and began to decrease after grain filling,and the temperature difference was reduced.The temperature stability of 10 cm soil was the highest.Under the influence of planting density,the soil temperature of high density treatment increased rapidly during the day,the temperature at night was the lowest,and the temperature difference between day and night was large,and the highest daily average temperature appeared earlier.The soil temperature of D1and D2treatments changed almost synchronously in 10 cm and 15 cm soil layers.In contrast,the occurrence time of Tmaxand Tminin different soil layers was postponed with the deepening of soi depth.Tavg,Tmaxand Tminwere positively correlated with air temperature during the whole growth period,while Tmax-mintended to decrease with the increase of density.The main effects were at tillering stage and filling stage,and the effect increased with the density.D2treatment had the highest yield of 9.27 t/hm2,increased by 13.5%-14.6%compared with D1and D5treatments.It showed that the appropriate density condition could realize the scientific regulation of the thermal effect of shallow soil layer and improve the yield.