• ISSN 1008-505X
  • CN 11-3996/S

喷施尿素硝酸铵提高夏玉米产量并降低氮肥用量和土壤氮素盈余

Foliar application of urea ammonium nitrate increases summer maize yield and reduces nitrogen input and soil nitrogen surplus

  • 摘要:
    目的 尿素分次追施是黄淮海夏玉米的常规施肥方法,但费事费力,播撒不匀还可能降低肥效,引发氮素损失。我们结合当前推广的微喷灌技术,研究了喷施尿素硝酸铵液体肥(UAN)替代土施尿素的可行性以及适宜的施肥量。
    方法 于2019和2020年,在泰安市岱岳区马庄镇开展田间试验,供试夏玉米品种为登海605 (DH605)和登海518 (DH518)。设沟施尿素-N 210 kg/hm2 (Ur),喷施UAN-N 126 kg/hm2 (U1,减氮40%)、168 kg/hm2 (U2,减氮20%)和210 kg/hm2 (U3)处理,以及1个不施氮对照 (N0)。在玉米抽雄期(VT)、成熟期(R6),采集植株样品分析不同部位氮素含量和干物质积累量,计算氮素吸收、运转和利用率。于玉米播前、拔节期(V6)、大喇叭口期(V12)、抽雄期(VT)、乳熟期(R3)和成熟期(R6),取0—20、20—40、40—60 cm土层土样,分析硝态氮和铵态氮含量,计算氮素残留和盈余量。
    结果 DH605和DH518两个玉米品种的产量均表现为U3处理显著高于U2和Ur处理,而U1处理显著低于U2和Ur处理,U3处理DH605的产量和净收益较Ur处理分别增加了6.71%和11.75%,DH518分别增加了7.57%和13.61%。干物质积累量、氮素积累量、氮素转运量和花后氮素同化量均随UAN用量的增加而增加,U3处理各指标均显著高于其他处理,两品种氮素回收率较Ur处理分别提高了20.78和19.22个百分点,氮素农学利用率分别增加了4.57和4.99 kg/kg。U2处理两品种玉米产量与Ur处理无显著差异,但植株氮素积累量、氮素转运量和花后氮素同化量高于Ur处理,最终提高了氮素回收率和氮素农学利用率。VT时期20—40 cm土层NO3-N含量随UAN施用量增加而增加。玉米VT至R6时期,各处理0—20 cm土层NO3-N含量基本呈降低趋势,Ur处理降低幅度最大,且喷施UAN处理与沟施尿素处理相比减少了玉米R6时期40—60 cm土层NO3-N含量,降低了氮素淋失潜在风险。此外,与Ur相比,喷施UAN处理降低了土壤氮素盈余,U3处理DH605和DH518两年分别平均降低43.63和40.36 kg/hm2,U2处理则分别平均降低了48.25和51.91 kg/hm2
    结论 在施氮量较传统用量减少20%的前提下,喷灌施用尿素硝酸铵溶液促进了玉米氮素积累和再分配,在保证产量的同时,可显著增加氮素回收率和氮素农学利用率,降低土壤NO3-N淋失的潜在风险和土壤氮素盈余,实现夏玉米生产减肥增效的目标。

     

    Abstract:
    Objective Base application plus one or two topdressing practices of urea is a conventional fertilization method in summer maize production of Huang-Huai-Hai Plain, which is time-consuming and laborious, and high in N loss risk. We studied the feasibility and appropriate amount of spraying urea ammonium nitrate liquid fertilizer (UAN), combing with the currently promoted micro-sprinkler irrigation technology.
    Methods Field experiments were conducted in Taian City, Shandong Province in 2019 and 2020, with summer maize hybrids Denghai 605 (DH605) and Denghai 518 (DH518) as test materials. The treatments included furrow application of urea-N 210 kg/hm2 (Ur), sprinkler application of UAN-N 126 kg/hm2 (U1, reducing N by 40%), 168 kg/hm2 (U2, reducing N by 20%), and 210 kg/hm2 (U3), as well as a no nitrogen fertilizer control. At the tasseling stage (VT) and physiological maturity stage (R6), plant samples were taken to analyze N content and dry matter accumulation in different parts for the calculation of N absorption, reallocation, and utilization efficiencies. Before sowing and at the sixth leaf stage (V6), the twelfth leaf stage (V12), tasseling stage (VT), milk stage (R3), and physiological maturity stage (R6), soil samples from 0–20 cm, 20–40 cm, and 40–60 cm depth were taken to analyze the nitrate and ammonium nitrogen content for the calculation of N residue and surplus in soil.
    Results The grain yields of hybrid DH605 and DH518 in U3 treatment were significantly higher than in U2 and Ur, while those in U1 were significantly lower than U2 and Ur. The grain yield and net income of hybrid DH605 under U3 were 6.71% and 11.75% higher than under Ur, while those of DH518 under U3 were 7.57% and 13.61% higher than under Ur, respectively. The dry matter accumulation, N accumulation, N transport and post-anthesis N assimilation amount all reached peaks in U3 treatment (P<0.05). Compared with Ur, the U3 treatment increased the N recovery rates of the two hybrids by 20.78 and 19.22 percentage points, N agronomic use efficiencies by 4.57 and 4.99 kg/kg, respectively. U2 treatment was recorded similar grain yields in the two hybrids with Ur, but enhanced plant N accumulation, transport and post-anthesis N assimilation, so led to significant higher N recovery and agronomic efficiencies than Ur. At the VT stage of maize, the NO3-N content in 20–40 cm soil layer increased with the increase of UAN application rate. From VT to R6 stage, the NO3-N content in 0–20 cm soil layer of each treatment showed a decreasing trend, with the highest decrease in Ur treatment. At the R6 stage, UAN treatment soils were recorded lower NO3-N content in 40–60 cm soil layer than Ur treatment, weakened the potential risk of NO3-N leaching. Compared with Ur, U3 decreased the N surplus in DH605 and DH518 experiment by 43.63 and 40.36 kg/hm2 on two year average, and U2 decreased those by 48.25 and 51.91 kg/hm2, respectively.
    Conclusions With 20% less of conventional N input, foliar application of urea ammonium nitrate liquid fertilizer with sprinkler irrigation stimulates the nitrogen accumulation and reallocation, and increases the nitrogen recovery and agronomic efficiencies while increase maize yield, and decrease the soil nitrogen surplus and NO3-N leaching risk, achieving the target of fertilizer reduction and profit improvement in summer maize production.

     

/

返回文章
返回