红黄壤是我国长江以南的热带和亚热带地区的重要农业土壤之一,其面积约占全国土地总面积的12%。这类土壤通常含有较高的交换性的铝,严重抑制作物生长,限制作物产量的提高。因此,施用石灰是改良红壤酸性、提高作物产量的必不可少’的措施。然而,我国农民施用石灰往往重水田.而轻旱地,因而造成 Red and yellow soil is one of the important agricultural soils in the tropical and subtropical regions south of the Yangtze River in the country. Its area accounts for about 12% of the total area of ​​the country. Such soils usually contain higher exchangeable aluminum, severely inhibiting crop growth and limiting crop yields. Therefore, the application of lime is an indispensable measure to improve the acidity of red soil and increase crop yield. However, the use of lime by peasants in our country tends to be heavy paddy fields, resulting in a slight drought