【摘要】：與傳統(tǒng)肥料相比,包膜緩控釋肥能有效減輕土壤氮素養(yǎng)分的流失。但目前大部分包膜材料均為高分子聚合物,難降解易累積,長(zhǎng)期使用極易破壞土壤結(jié)構(gòu)。因此尋求新的緩釋包膜材料,制備環(huán)境友好型緩釋肥是目前該領(lǐng)域研究的熱點(diǎn)。另一方面,我國(guó)水稻秸稈資源豐富,但秸稈還田往往促進(jìn)稻田甲烷等溫室氣體的排放。生物質(zhì)炭具有高度穩(wěn)定性和較強(qiáng)的養(yǎng)分吸附持留特性,具備作為緩釋肥包膜材料的基本要求。如果能將水稻秸稈炭化用于制備緩釋肥,則無(wú)疑將為水稻秸稈資源化利用和環(huán)保型緩釋肥生產(chǎn)提供一條新技術(shù)途徑,也將為我國(guó)農(nóng)田生態(tài)系統(tǒng)面源污染防治和農(nóng)業(yè)固碳減排作出重大貢獻(xiàn)�；诖�,本論文通過(guò)采用自燃內(nèi)熱式炭化爐,以水稻秸稈為原料,開(kāi)展了秸稈生物質(zhì)炭化中試生產(chǎn)試驗(yàn)；借助正交試驗(yàn),以秸稈生物質(zhì)炭為主料,優(yōu)化制備適合水稻生長(zhǎng)的炭基緩釋肥；并在盆栽和大田試驗(yàn)條件下驗(yàn)證了炭基緩釋肥對(duì)水稻生產(chǎn)和稻田氮素流失的影響。主要研究結(jié)果如下： (1)借助具有自主知識(shí)產(chǎn)權(quán)的自燃內(nèi)熱式炭化爐,以水稻秸稈為試材,綜合考察風(fēng)機(jī)進(jìn)風(fēng)量和炭化停留時(shí)間對(duì)生物質(zhì)炭炭化得率和碳含量的影響。結(jié)果表明進(jìn)風(fēng)量為2600m3/h和停留時(shí)間為1h的運(yùn)行條件下制備得到的生物質(zhì)炭比較適合用作制備炭基緩釋肥的研究材料。在該條件下,水稻秸稈經(jīng)400-500℃炭化后,生物質(zhì)炭的得率可達(dá)34.9%,碳含量高達(dá)53.67%。 (2)以秸稈生物質(zhì)炭和普通復(fù)合肥料為基料,通過(guò)正交試驗(yàn),比較分析了生物質(zhì)炭、膨潤(rùn)土與煤炭腐殖酸含量以及粘結(jié)劑類型對(duì)炭基緩釋肥中氮養(yǎng)分緩釋效果的影響。結(jié)果發(fā)現(xiàn)生物質(zhì)炭含量為25%,膨潤(rùn)土含量為4%,煤炭腐殖酸含量10%,并以改性玉米淀粉為粘結(jié)劑條件下制備的炭基包膜緩釋肥緩釋效果最佳,達(dá)到國(guó)家緩釋肥料標(biāo)準(zhǔn)(GB/T23348-2009)要求。生物質(zhì)炭組分含量變化對(duì)包膜緩釋肥緩釋效果影響最大。生物質(zhì)炭與膨潤(rùn)土、煤炭腐殖酸相互作用在肥芯外形成緊致膜層可能是制備的炭基緩釋肥具備高效緩釋性能的主要原因。 (3)以秸稈生物質(zhì)炭和炭基緩釋肥為試材,通過(guò)盆栽和大田實(shí)驗(yàn),初步考察了炭基緩釋肥施用對(duì)稻田氮素流失與水稻產(chǎn)量的影響。大田實(shí)驗(yàn)結(jié)果表明,與CK相比,SRFA的施用可以使水稻產(chǎn)量增加7.7%。人工模擬降雨實(shí)驗(yàn)結(jié)果表明,在相同雨量條件下,與對(duì)照相比,炭基緩釋肥施用可削減徑流總氮流失量27.3%-56.6%。通過(guò)對(duì)大田施肥后田面水的總氮濃度進(jìn)行多項(xiàng)式擬合,CK的二次項(xiàng)系數(shù)0.0329SRFA的二次項(xiàng)系數(shù)0.0188,表明與CK相比,SRFA可以緩慢釋放養(yǎng)分,有利于降低稻田氮素養(yǎng)分流失風(fēng)險(xiǎn)和水稻增產(chǎn)。
[Abstract]:Compared with traditional fertilizer, coated controlled release fertilizer can effectively reduce soil nitrogen loss. However, most of the coating materials are polymeric polymers, which are difficult to be degraded and accumulated, and can easily destroy soil structure for long term use. Therefore, it is a hotspot in this field to seek new sustained-release coating materials and prepare environmentally friendly sustained-release fertilizer. On the other hand, rice straw resources are abundant in China, but straw returning often promotes methane emissions. Biomass carbon has the characteristics of high stability and strong nutrient retention, and has the basic requirements as the coated material of slow-release fertilizer. If rice straw carbonization can be used to produce slow-release fertilizer, it will undoubtedly provide a new technical approach for the utilization of rice straw and the production of environment-friendly slow-release fertilizer. It will also contribute to the prevention and control of agricultural ecosystem non-point source pollution and the reduction of carbon sequestration in agriculture. Based on this, the pilot production experiment of straw biomass carbonization was carried out by using autoignition internal heat carbonization furnace and rice straw as raw material, and straw biomass carbon was used as main material by orthogonal test. The effects of carbon-based slow-release fertilizer on rice production and nitrogen loss in paddy field were tested in pot and field experiments. The main results are as follows: (1) the effects of air intake and residence time of blower on the carbonization yield and carbon content of biomass were investigated with the help of spontaneous combustion internal heat carbonization furnace with independent intellectual property rights and rice straw as test material. The results showed that the biomass carbon prepared under the conditions of air intake 2600m3/h and residence time 1 h was suitable for the preparation of carbon-based slow-release fertilizer. Under these conditions, after carbonization of rice straw at 400-500 鈩，

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