钾肥对香稻产量及光合生产特征的影响

Changes of yield and photosynthetic production of aromatic rice in response to potassium application

为了探明钾肥对香稻产量及光合生产特征的影响,以常规香稻品种桂香占和农香18为材料,研究0 kg/hm2（对照）、37.5 kg/hm2、112.5 kg/hm2和187.5 kg/hm2 4个钾肥水平下的香稻产量及其构成因素、净光合速率、叶面积指数、光合势、叶绿素相对含量和干物质积累量等.结果显示,与不施钾肥对照相比,3个施钾处理均可显著提高2个香稻品种的产量.其中,在187.5 kg/hm2施钾水平下,桂香占的产量最高;在112.5 kg/hm2施钾水平下,农香18的产量最高.此外,112.5 kg/hm2和187.5 kg/hm2施钾水平下2个香稻品种的叶绿素相对含量、叶面积指数、光合势、净光合速率和干物质积累量均高于其他处理.表明钾肥能够提高香稻品种的光合生产能力,促进干物质的积累,增加香稻产量,在本试验条件下,较适宜的钾肥施用量为112.5～187.5 kg/hm2.

A field experiment was conducted to investigate yield and its components, net photosynthetic rate, leaf ar-ea index （LAI）, photosynthetic potential, relative chlorophyll content （SPAD） and dry matter accumulation of two conven-tional aromatic rice cultivars, Guixiangzhan and Nongxiang 18, under four potassium application rates 0 kg/ hm2 （CK）,37.5 kg/ hm2 , 112.5 kg/ hm2 and 187.5 kg/ hm2 . Compared with CK, potassium application significantly increased theyields of two aromatic rice cultivars. Guixiangzhan achieved the highest yield in 187.5 kg/ hm2 K2 O application treatment,and Nongxiang 18 reached the highest in 112.5 kg/ hm2 K2 O treatment. Potassium application rates at 112.5 kg/ hm2 and187.5 kg/ hm2 improved SPAD, LAI, photosynthetic potentials, net photosynthetic rates and dry matter accumulations oftwo aromatic rice cultivars. Therefore, potassium fertilization could promote the capacity of photosynthesis, the dry matteraccumulation and the yield of aromatic rice at the rates from 112.5 to 187.5 kg/ hm2 .