稻草全量還田下化肥運(yùn)籌對土壤肥力和水稻產(chǎn)量的影響?

摘 要：為了探明稻草與化肥減量配施對土壤肥力和水稻產(chǎn)量的影響，通過連續(xù)3 a田間定位試驗，研究了稻草全量還田條件下化肥運(yùn)籌（化肥100%、80%、60%、40%）對土壤肥力性狀和水稻產(chǎn)量變化特征的影響，以常規(guī)施用化肥為對照。結(jié)果表明：稻草全量還田能降低土壤容重、增加土壤孔隙度、提高土壤結(jié)構(gòu)穩(wěn)定性，提升有機(jī)質(zhì)及速效養(yǎng)分含量，改善土壤理化性狀且提高水稻產(chǎn)量；稻草全量還田條件下，隨著化肥用量減少，土壤物理性狀、pH值、有機(jī)質(zhì)含量變化不明顯，但速效養(yǎng)分逐漸下降，水稻產(chǎn)量隨之降低；其中，以稻草全量還田配施80%化肥的綜合效果最好，土壤容重降低了0.06 g/cm3，有機(jī)質(zhì)增加了2.8 g/kg，產(chǎn)量略有降低，但是差異不顯著。因此，綜合考慮稻田土壤肥力性狀、水稻產(chǎn)量、化肥用量等因素，筆者建議在湘西中稻種植區(qū)采用稻草全量還田配施80%化肥的施肥方法。

關(guān)鍵詞：稻草還田；化肥運(yùn)籌；水稻；土壤養(yǎng)分；水稻產(chǎn)量

中圖分類號：S158.5 文獻(xiàn)標(biāo)識碼：A 文章編號：1006-060X（2023）07-0054-03

Abstract：A three-year field positioning experiment was conducted to study the effects of total straw returning to the field accompanying chemical fertilizer reduction （100%， 80%， 60% and 40% application rate） on the change of soil fertility and rice yield， with the routine chemical fertilizer application as the control. The results showed that total straw returning could reduce soil bulk density， increase soil porosity， improve soil structure stability， increase organic matter and available nutrient contents， improve soil physicochemical properties， and increase rice yield. Under the condition of total straw returning to the field， with the decrease of chemical fertilizer dosage， the soil physical properties， soil pH and soil organic matter content did not change significantly， but the available nutrients gradually decreased， thereby the rice yield accordingly decreased. The effect of total straw returning along with 80% chemical fertilizer application （T3） was the best： the soil bulk density decreased by 0.06 g/cm3， the organic matter increased by 2.8 g/kg， though the yield decreased slightly， no significant difference existed. Comprehensively considering the factors of soil fertility， rice yield and chemical fertlilizer amount， the authors suggest that the total straw returning to the field should be combined with 80% chemical fertilizer amount in the middle-season rice planting area in western Hunan Province.

Key words：straw returning to field; chemical fertilizer management; rice; soil nutrients; rice yield

稻草還田是人類對自然生態(tài)系統(tǒng)物質(zhì)循環(huán)過程的模擬，是秸稈資源再利用的重要途徑[1-2]。我國秸稈資源豐富，其中稻草約占1/4，稻草中含有大量的氮、磷、鉀、硅等礦質(zhì)營養(yǎng)元素和有機(jī)碳，還有豐富的微量元素[3-4]。大量研究表明，稻草還田腐解后能增加土壤有機(jī)質(zhì)的積累，改變土壤腐殖質(zhì)組成和特征，緩解土壤氮、磷、鉀肥比例失調(diào)，彌補(bǔ)磷、鉀肥的不足，還能增強(qiáng)微生物活性，對提升地力、改善土壤環(huán)境、促進(jìn)作物生長發(fā)育和提高作物產(chǎn)量有十分重要的意義[5]。……