Agro-ecological studies on the ecosystem of field crops in arid lands

干旱和半干旱地区面积巨大，占地球陆地面积的28%。除个别地区外，这些地区的植物栽培技术水平明显偏低。本研究的目的是科学地阐明这些地区耕地生产力的上限和影响耕地生产力的因素。下加利福尼亚半岛属于半热带高气压区，中心位于北纬30度，位于北半球边界和锋面南部边界之间。此外，为了使流入半岛以南的太平洋近海的加州海流使洋流上方的大气层中的温度降低。随后，虽然湿度相对较高，但几乎不下雨的沿海沙漠气候出现。在黎明前的一天最低温度的时候，它变成了90%的湿度。相反，土壤表面和植物叶片受到影响 关于我们 通过辐射冷却，并且在可行的风速的情况下，它们的温度比大气温度低2至3 ℃或低于露点。在他们的表面上形成了露水。每100平方厘米的露水量约为2至3克。在半干旱或干旱荒漠地区，可作为水资源积极利用。此外，露水被认为对自然生长的植被也有很大的影响。通过在土壤中掺入保水物质进行几种蔬菜的限水栽培。结果表明，格雷罗内格罗具有较高的蔬菜生产潜力。农业是受大自然影响较大的本土或土著产业。因此，仅凭2 ~ 3年的试验数据来讨论这些地区的农业栽培方式是否适应或适宜是很危险的。努力增加试验的次数，其中重复种植相同或蔬菜，以尽可能减少危险。但是，由于时间的限制，国外学术界的研究成果还不多，有些事情我们必须尽快得出结论，但多少有些遗憾。少

Arid and semi-arid regions are extremely huge, amounting to 28% of lands in the Earth. Technologies of plant-cultivation in these areas are markedly at low level except for in particular regions. Our research was aimed at clarifying scientifically an upper limit of both productivity in ploughed fields in these areas and factors retarding the productivity. The Baja California Peninsula belongs to a semi-torrid high atomospheric zone, centering in latitude 30 N and is located in between a nothern limit and southern one of the front. Furthermore, in order that the California Sea Current flowing in to an offshore of the Pacific Ocean south of the peninsula, causes temperature in an atomosphere over the ocean current to diminish. Subsequently, although humidity is relatively high, the coastal desert climate in which it scarcely rains occurs. At a time of daily minimum temperature before daybreak it becomes 90% in humidity. On the contrary, soil-surface and leaves of plant are put influences … More on by radiant cooling, and in a case of feasible wind rate their temperatures get lower by 2 to 3 c than the atomospheric temperature or become below a dew point. Thus dew formed on their surfaces. The amount of dew is nearly 2 to 3g per 100 cm^2. The quantity is considered to be utilized positively as water-resource in the semi-arid or arid desert. Moreover, the dew is thought to have great influences on naturallygrowing vegetation as well. Several sorts of vegetable-cultivation were performed by mixing in the soil water-holding substance as water-limiting cultivation. Such result was gotten that Guerrero Negro had potentially high productivity related to vegetable-cultivation. Agriculture is native or indigenous industry affected great influences by nature. Therefor, it is very dangerous to discuss whether or not ways of the cultivation in agriculture in those regions are adaptable or appropriate with only the experimental data collected for 2 to 3 years. Efforts to rising the number of the test in which the cultivations of the same or vegetables were repeated, were made to minimize the very danger as much as possible. Anyhow, it would be added that there are affairs that we must hurry up to make conclusion, somehow with a regret, owing to limitation retative to time depending on the overseas academic research. Less