氮肥运筹对夏玉米产量、氮素利用率及土壤养分残留量的影响

通过2年定位试验,在山西省临汾市采用大田随机区组试验法,在等氮磷钾施肥条件下,研究氮肥运筹对夏玉米产量及其构成因素、不同生育期植株氮磷钾吸收量,并监测0~40 cm土壤速效养分含量动态变化。结果表明,施氮肥处理均使不施氮肥处理(CK)夏玉米显著增产,2014,2015年增产幅度分别为5.72%~27.71%和6.05%~27.84%;其中,一次性施用缓控释肥处理BBF和CRF的夏玉米产量接近或高于常规尿素3次施肥(U3)和2次施肥(U2),增产效果优于一次性基施等量普通复合肥(CF)处理;BBF和CRF处理夏玉米穗粒数、单穗粒重和百粒质量等产量构成因素指标均较优,与U3处理间差异不显著;BBF和CRF处理下植株氮磷钾养分积累量高是产量提高的基础,2年氮肥表观利用率平均达29.59%和28.95%,高于CF处理(22.27%)。常规尿素分次施肥处理施肥次数越多,玉米产量和氮肥利用率越高。各施氮肥处理对土壤速效养分残留量影响在不同生育期各异。BBF和CRF处理0~20 cm土层碱解氮含量随玉米生育期表现为先低后高再低的趋势,这与玉米整个生育期氮素吸收形成一定协同效应,且生育后期残留量低。各施氮肥处理20~40 cm土壤碱解氮含量在苗期变化不大,大喇叭口期和成熟期以U1和U2增加明显。与CK相比,各施氮处理玉米收获后0~40 cm土壤碱解氮残留量均增加。0~20 cm和20~40 cm土壤速效磷和缓效钾含量在生育期的差异较施氮处理间的差异更明显。因此,一次性基施缓控释肥可达到接近或增加常规尿素2次或3次施肥对夏玉米的增产效果,较好地协调养分供应与夏玉米养分吸收,提高氮素养分利用率,后期土壤养分残留量低,实现夏玉米一次性施肥高产高效的效果。

Effects of Nitrogen Application on Summer Maize Yield,Nutrient Utilization Efficiency and Soil Available Nutrient Residues

The experiment aimed to study the fertilizer practice for realizing the target of simplify,high yield and high efficiency fertilization of summer maize.Under the same application rates of N,P and K,field experiment was conducted to study the characteristic of the yield and its components,nutrient absorption and accumulation and available nutrient content of 0-40 cm soil layer in different growth period of summer maize in 2014 and 2015.Control to no nitrogen treatment (CK),applying nitrogen treatments increased the yield of summer maize,ranging from 5.72％ to 27.71％ in 2014 and 6.05％ to 27.84％ in 2015.Controlled-release fertilizers (BBF and CRF) and conventional fertilizer application (U3) had higher maize yields with no significant difference,and higher than those in CF and U2.Furthermore,grains per ear,grain weight per ear and 100-grain ear in BBF and CRF was better than other treatments,while had no significant difference with U3.Total N,P and K uptake under BBF and CRF provided the basis for higher yield,N apparent utilization efficiency in BBF and CRF was 29.59％ and 28.95％,which was higher than those in CF (22.27％).Maize yield and N apparent utilization efficiency was higher,the more times of conventional fertilizer application (U1,U2,U3).Soil available nutrient residue in apply ing nitrogen treatments were difference under different growth period.0-20 cm soil layer alkalystic N content showed a low-high-low trend under single basal controlled-release fertilizer BBF and CRF,which consistent with maize nitrogen absorption,and lower residue in late growth period.Littlechange of soil alkalystic N content under nitrogen treatments was found in 20-40 cm soil layer in seedling stage,while higher residues was observed under U1 and U2.Control with CK,after maize harvest,soil alkalystic N residue under nitrogen treatments in 0-40 cm was increased.0-20 cm and 20-40 cm soil available P and K had far more difference in growth period than applying nitrogen treatments.Applying BBF and CRF were beneficial to realize single application of base fertilizer and realizing the aim of simplify,high yield and high efficiency fertilization by increasing N,P and K absorption and accumulation,improving N apparent utilization efficiency and presenting lower soil nutrient residues.