石灰性土壤马铃薯根区调酸促生机理的研究

Potato in calcareous soil had grown a lot, but there existed a contradiction between the potato like acid (the optimal pH 5.0～5.5) and the calcareous soil was alkaline (pH 7.5～8.5) and the high pH was unfavorable on the yield formation and quality improvement of the potato. By simulation test researching different materials on the acid effect of calcareous soil, this project would screen the best acid agent to establish the forecast model of the effect of acid. Through field experiment, we explored the effect of the acid concentration in the root zone of potato growing period after the concentration of the acid in the calcareous soil. From the two aspects of soil and crop, the mechanism of promoting the growth of potato was revealed in the following aspects. Soil focuses on effects of acid on soil nutrient effectiveness , key enzymes and microbial activity fertility index; crops focuses on regulating acid on the growth index of underground and above ground of potato, nutrient uptake and accumulation characteristics, physiological and biochemical indexes, yield formation process and influence. To find out the effect and mechanism of acid regulating agent in the field of potato root zone, had important theoretical significance and practical guiding value for high yield and high efficiency cultivation and formation of potato high efficiency special fertilizer products. Data review shows that the present domestic and foreign had not been found in the lime soil potato acid adjustment system, the results of the research would fill the blank.

石灰性土壤上马铃薯种植面积较大，但马铃薯喜酸性（最适宜pH值5.0～5.5）与石灰性土壤偏碱性（pH值7.5-8.5）存在矛盾，高pH值对马铃薯产量形成、品质改善都是不利的。项目将通过模拟试验研究不同材料对石灰性土壤的调酸效应，筛选最佳调酸剂，建立其调酸效果的预测模型；通过田间试验，探索石灰性土壤集中施用调酸剂后对马铃薯生育期根区的调酸效果，从土壤和作物二方面揭示调酸后对马铃薯促生机理。土壤方面重点研究调酸对土壤养分有效性、关键酶及微生物活性等肥力指标的影响；作物方面重点研究调酸对马铃薯地下与地上生长指标、养分吸收与累积特性、生理生化指标、产量形成过程等的影响。探索调酸剂田间对马铃薯根区的调酸效应及促生机理，对马铃薯高产高效栽培和研制马铃薯高效专用肥料均具有重要理论意义和实践指导价值。资料综述表明，目前国内外尚未见石灰性土壤马铃薯调酸促生作用方面的系统报道，研究成果将填补其空白。

马铃薯在石灰性土壤上有大量种植，但马铃薯喜酸性（最适宜pH值5.0～5.5）与石灰性土壤偏碱性（pH值7.5～8.5）存在矛盾，高pH值对马铃薯产量形成、品质改善都是不利的。项目通过模拟试验和田间试验研究了调酸材料对石灰性土壤的调酸效应，探索了石灰性土壤集中施用调酸剂后对马铃薯生育期根区的调酸效应，从土壤和作物二方面揭示调酸后对马铃薯促生作用。主要研究结果：. 1．明确了不同调酸材料对石灰性土壤的调酸效应 . 单一调酸材料调酸效果表现为磷酸一铵效果最好，其次为硫磺和颗粒硫肥。复配调酸剂调酸效果表现为磷酸一铵和硫磺复配调酸效果最。这一研究结果为调酸材料的生产应用提供了理论和技术支撑.2．明确了复配调酸剂田间施用对石灰性土壤的养分和生物效应. 复配调酸材料通过扩散调酸和材料的共同作用，使土壤有效氮、有效磷、有效锌和有效硼含量增加，但降低了土壤速效钾含量；复配调酸剂的施用使土壤细菌多样性增加，这种改变与土壤pH的变化呈显著相关性；调酸材料施入土壤过氧化氢酶活性增加、脲酶活性降低。土壤有效养分和生物多样性的改变，说明调酸材料在改变土壤pH时也直接改变了土壤的养分供应能力，生物多样性的改变间接影响土壤养分的有效性，是促进马铃薯生长的物质基础。.3.明确了复配调酸剂田间施用对马铃薯生长和生理效应. 复合调酸材料施入土壤后，促进了马铃薯的生长，表现为分支、株高、茎粗和生长期干物质量的增加；植株茎叶的全氮含量块茎形成期和膨大期增加，淀粉累积期含量降低，但对马铃薯茎叶全磷、全钾含量影响较小；调酸剂能够显著增加马铃薯叶片的叶绿素含量。复合调酸材料施入土壤后马铃薯产量明显提高，但品质方面降低了薯块淀粉、Vc及蛋白质含量，这与产量的提高有直接关系。复合调酸剂用量不同产生的作用不同，综合考虑，AM2处理（复合调酸剂450㎏/hm2）对马铃薯的生长效应较好。上述结果从马铃薯生长过程揭示调酸剂的作用，也是复合调酸剂合理施用的重要依据。.