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“农艺生物强化”策略认为,生产出富含微量营养素的粮食作物说明产出微量营养素密集的食物是一个有效的农业措施。全球范围内大部分谷物耕地的土壤中物理和化学成分都欠佳,如土壤中有机质和含水量低而pH值和碳酸钙含量高。这种不利的土壤条件会严重降低土壤的化学溶解能力和植物根部吸收微量营养素的能力,尤其是锌和铁。例如,把土壤的pH值提高到碱性范围(pH6.5或更高),溶解度会降低(数倍),锌运输到根系表面的能力也会降低。在一个对花生的研究中发现,把土壤的pH值从5.2提高到6.8,则花生叶子中锌的含量从200毫克/公斤降低至20毫克/公斤(Parker和Walker,1986)。已发表的数据表明,土壤有机质和土壤根际可溶性锌浓度之间存在较强的正相关关系(Catlett等人.,2002),强调土壤有机质对植物根部吸收锌的重要性。因此,粮食作物的种子或新开发的生物强化品种种子从化学成分欠佳的土壤中吸收微量营养素会使种子中锌浓度难以达到理想的状态。所以,对以食物来补充微量营养素的人群来说,加强农艺生物强化(施肥)是十分必要的策略,也许还有助于耕地资源匮乏的地区提高作物的产量。
The Agronomy Strategy believes that the production of micronutrient-enriched food crops is an effective agricultural measure to produce micronutrient-dense foods. Most of the arable land in the world has poor physical and chemical composition of the soil such as low organic matter and water content in the soil and high levels of pH and calcium carbonate. This unfavorable soil condition severely reduces the chemical solubilization of the soil and the ability of plant roots to absorb micronutrients, especially zinc and iron. For example, increasing soil pH to the alkaline range (pH 6.5 or higher) decreases solubility (several fold) and zinc’s ability to transport to root surfaces also decreases. In a study of peanuts, it was found that increasing soil pH from 5.2 to 6.8 reduced the zinc content of peanut leaves from 200 mg / kg to 20 mg / kg (Parker and Walker, 1986). Published data indicate a strong positive correlation between soil organic matter and rhizosphere soluble zinc concentrations in soil (Catlett et al., 2002), emphasizing the importance of soil organic matter to zinc uptake by plant roots. As a result, seeds of seed crops or newly developed biostimulated seeds that absorb micronutrients from poorly-chemically-fortified soils can make it difficult to achieve optimal zinc concentrations in the seeds. Therefore, strengthening agronomic biofuels (fertilizers) is a very necessary strategy for people who supplement their micronutrients with food and may also help increase crop yields in areas where cultivated land is scarcer.