Agro-ecological Survey of Ultisol-Oxisol Area in South America

为了了解南美洲热带地区的农业生态状况，对从巴西中部到西部的地区进行了调查。(1)巴西高地(塞拉多)的特点是气候干燥，高地辽阔，有棕壤。在旱地上，牧草-肉牛系统一直很常见，但近年来粮食作物系统发展迅速。(2)Pantanal是一片广袤的低地，每年季节性洪水泛滥，被肥沃的Entisols占据。季节性肉牛制度是该地区特有的耕作制度。(3)亚马孙上盆地气候湿润，低地广袤，土壤层多，热带雨林多。这一地区的造假活动仍然很少。(4)过渡区农业生态条件介于塞拉多和热带雨林之间。(5)瓦泽亚大面积的灌溉稻田管理良好，表明整个调查区灌溉水稻的生产潜力很大。(6)迫切需要收集有关自然和人为环境的光合作用能力和水土保持能力的可靠数据，以便能够预测该地区植被大规模变化对全球的影响。

To understand the agro-ecological condition in tropical South America, the area extending from central to western Brazil was surveyed. (1) Brazilian Highland(Cerrado) is characterized by a dry climate and vast uplands with Oxisols. On the uplands, pasture-beef cattle system has been common, but grain crop systems are growing rapidly in recent years. (2) Pantanal is a vast lowland which is flooded seasonally every year, and is occupied by fertile Entisols. Seasonal beef-cattle system is a unique farming system in this region. (3) Upper Amazon Basin is characterized by humid climate, vast lowlands with Inceptisols or Entisols and tropical rain forest. Framing activities in this region are yet low. (4) The agro-ecological condition of Transition Region is intermediate between that in Cerrado and in rain forest. (5) Vast irrigated rice fields in Varzea are well managed and demonstrate that the potential of irrigated rice production is high throughout the survey area. (6) It is urgently needed to collect reliable data on photosynthetic capacity and water and soil conservation capacity of natural and manmade environments to enable the prediction of global influence caused by large scale modification of vegetation in this area.