Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Sciences and Natural Resource Management (MINA), Norwegian University of Life sciences (NMBU), Ås, Norway; Nepal Agroforestry Foundation (NAF), Koteshwor, Kathmandu, Nepal.
Faculty of Environmental Sciences and Natural Resource Management (MINA), Norwegian University of Life sciences (NMBU), Ås, Norway.
Sci Total Environ. 2018 Jun 1;625:1380-1389. doi: 10.1016/j.scitotenv.2018.01.022. Epub 2018 Jan 12.
We studied the role of biochar in improving soil fertility for maize production. The effects of biochar on the alleviation of three potential physical-chemical soil limitations for maize growth were investigated, i.e. water stress, nutrient stress and acid stress. Experiments involved soils with two dosages of biochar (0.5% and 2% w:w), as well as ones without biochar, in combination with four different dosages of NPK fertilizer, water and lime. Biochar was produced from the invasive shrubby weed Eupatorium adenophorum using flame curtain kilns. This is the first study to alleviate one by one the water stress, nutrient stress and acid stress in order to investigate the mechanisms of biochar effects on soil fertility. Biochar addition increased soil moisture, potassium (K) and plant available phosphorous (P-AL), which all showed significant positive relationship (p<0.001) with above ground biomass of maize. However, biochar was much more effective at abundant soil watering (+311% biomass) than at water-starved conditions (+67% biomass), indicating that biochar did increase soil moisture, but that this was not the main reason for the positive biomass growth effects. Biochar addition did have a stronger effect under nutrient-stressed conditions (+363%) than under abundant nutrient application (+132%). Biochar amendment increased soil pH, but liming and pH had no effect on maize dry biomass, so acidity stress alleviation was not the mechanism of biochar effects on soil fertility. In conclusion, the alleviation of nutrient stress was the probably the main factor contributing to the increased maize biomass production upon biochar addition to this moderately acidic Inceptisol.
我们研究了生物炭在提高玉米生产土壤肥力方面的作用。研究了生物炭对缓解玉米生长的三种潜在理化土壤限制的作用，即水分胁迫、养分胁迫和酸胁迫。实验涉及到两种生物炭剂量（0.5%和 2%w:w）的土壤，以及没有生物炭的土壤，以及与四种不同剂量的 NPK 肥料、水和石灰结合。生物炭是用火焰幕窑从入侵性灌木杂草紫茎泽兰中生产的。这是首次一项一项地缓解水分胁迫、养分胁迫和酸胁迫，以研究生物炭对土壤肥力的作用机制。生物炭的添加增加了土壤水分、钾（K）和植物有效磷（P-AL），它们都与玉米地上生物量呈显著正相关（p<0.001）。然而，生物炭在土壤水分充足时（+311%生物量）比在缺水时（+67%生物量）更有效，这表明生物炭确实增加了土壤水分，但这不是生物炭对生物量增长的积极影响的主要原因。在养分胁迫条件下（+363%），生物炭的添加效果比在养分充足的情况下（+132%）更强。生物炭改良增加了土壤 pH 值，但石灰和 pH 值对玉米干生物量没有影响，因此酸胁迫缓解不是生物炭对土壤肥力的作用机制。总之，缓解养分胁迫可能是生物炭添加到这种中度酸性的始成土中增加玉米生物量的主要因素。
