桐城县位于大别山麓,长江北岸,北纬31度。全县63万亩水稻田,山区占24%,丘陵占40%,这两种地区都是水利差、土层浅、土质瘦。群众说是:“拉屎不生蛆、靠天收的地方”.圩坂田占36%,虽然土质较好,但因常受洪涝灾害。群众说:“看母猪、插圩田、收一年算一年”。所以解放前产量只有300斤左右。年平均温度14.8度,无霜期220——230天,年雨量1,200—1,500毫米左右,且分布不均匀,春夏之交 Tongcheng County is located in the foothills of the Dabie, north shore of the Yangtze River, 31 degrees north latitude. The county 630000 acres of paddy fields, mountains accounted for 24%, hills 40%, both areas are poor water, shallow soil, thin soil. The masses said: “shit does not produce maggots, close by the days of income.” Wei Bantian accounted for 36%, although the soil is better, but often due to floods. The masses said: “Look at the sow, insert the polder, receive a year as a year.” Therefore, before the liberation yield of only 300 pounds. The average annual temperature of 14.8 degrees, 220-230 days frost-free period, annual rainfall of about 1,200-1,500 mm, and the uneven distribution of the spring and summer