Quantity of Nitrogen Fertilizer for New Early Rice Variety Yongxian 975

Lincan JIN,Xianbo SHI,Tao HUANG,Feijun WANG

1.Ningbo City Academy of Agricultural Sciences,Ningbo 315040,China;

2.Agricultural Technology Service Station of Fenghua City,Fenghua 315500,China

Quantity of Nitrogen Fertilizer for New Early Rice Variety Yongxian 975

Lincan JIN1*,Xianbo SHI1,Tao HUANG2,Feijun WANG2

1.Ningbo City Academy of Agricultural Sciences,Ningbo 315040,China;

2.Agricultural Technology Service Station of Fenghua City,Fenghua 315500,China

[Objective]The study was to test the optimum quantity of nitrogen fertilizer of Yongxian 975. [Method]According to randomized block arrangement with three replications,there were 5 nitrogen fertilizer treatments and 1 blank control,the net area of each plot was 13.4 m2.[Result]There was no significant difference between different nitrogen fertilizer treatments.The spike,grain and weight were more coordinated and the yield-increasing potential was great when the quantity of pure nitrogen was 210.0 kg/hm2.The real harvest yield was the highest and the profit was the best,but the utilization rate of fertilizer was poor,plant diseases,insect pests, lodging risk and the ecological burden were increased when the quantity of pure nitrogen was 270.0 kg/hm2.While the quantity of pure nitrogen was 150.0 kg/hm2, the fertilizer utilization rate was the highest,the yield and the economic benefit were high. [Conclusion]With comprehensively considering the high and stable yield and the efficiency,the best quantity of nitrogen fertilizer on Yongxian 975 was controlled at about 150.0 kg/hm2.The quantity of pure nitrogen could be increased to 180.0 kg/hm2when the field fertility was moderate or low.In order to explore its high-yield potential,the quantity of nitrogen fertilizer could be increased to 210.0 kg/hm2in the high-yield tackling field.

Early rice;Yongxian 975;Quantity of nitrogen fertilizer

Y ongxian 975 is a new medium maturing and early indica variety bred by Ningbo City A cademy of Agricultural Sciences,and it was examined and approved by Zhehjiang Provincial Variety Examination and ApprovalCommittee in February of 2014.The variety has short plant,strong tillering ability,good 1 000-seed weight,good lodging resistance,yellow ripe stalk in the later period and good yielding ability,it is suitable to plant as early season rice in Zhejiang Province.The average yield per unit area in the regional trial of Zhejiang Province in two years was 7 236.0 kg/hm2,which was higher than Jinzao 47(CK)by 7.8%.The average yield per unit area in the production testing of Zhejiang Province in 2013 was 7 096.5 kg/hm2,which was higher than Jinzao 47(CK)by 7.3%.In the experiment,demonstration and popularization of Yongxian 975 in recent years,it was found that Yongxian 975 is very sensitive to nitrogenous fertilizer,which directly affects its colouring and setting percentage at the filling and ripening stage.Thus the quantitative research of nitrogenous fertilizer for Yongxian 975 is especially important for future application and extension.

Materials and Methods

Experimental site and soil conditions

The experiment was carried out at Xiaxu Village,Xiwu Street,Fenghua City,the preceding crop of experimental field was winter fallow land with blue purple clay soil.By testing,the organic content in the soil was 5.71%, pH was 4.88,hydrolysable nitrogen, available phosphorus,rapidly available potassium and total water soluble salt were respectively 272 mg/kg,20.1 mg/kg,108 mg/kg and 0.91 g/kg,thus it was high fertility soil.

Experimental fertilizers

Nitrogenous fertilizers:urea(contains 46%N)and ammonium bicarbonate(contains 17.1%N);phosphatic fertilizer:superphosphate(contains 12%P2O5);potash fertilizer:potassium chloride(contains 60%K2O).

Experimental treatment and design

Total amount of nitrogen fertilizer was set as the only factor;6 treatments on total amount of nitrogen fertilizer were set up,which separately were 270.0,240.0,210.0,180.0 and 150.0 kg/hm2pure nitrogen,and no fertilizer(CK);the net area of each plot was 13.4 m2;there was randomized block arrangement with three replications.

The application method was based on the summary of experience obtained from the study on the nitrogen application characteristics of early season rice variety of previous Yongxian series,base fertilizer:fertilizer for seed bed:fertilizer for head sprouting= 1:2:0 was better[1-2].The types and quantity of nitrogen fertilizer of each treatment were in Table 1.

Overview of experiment

Earth ridge was piled around the experimental plot,and it was surrounded with black plastic film to prevent the mutual leakage of fertilizer, each plot had independent irrigation and drainage system,and guard row was set around the experimental field. Ammonium bicarbonate and urea were respectively used as base fertilizer and fertilizer for seed bed.After raking,375.0 kg/hm2superphosphate was applied,ammonium bicarbonate was used as leavening dough after the successful establishment of plot,fertilizer for seed bed and 112.5 kg/hm2potassium chloride were together applied on the 7thand 18thd after sowing. Forothermanagement,localfield management level can be referred to.

In the experiment,the sowing and transplanting dates were respectively on April 5 and May 2.One day before transplanting,the quality of seedlings was examined,it was measured that the height of seedlings was 18.7 cm, the base stem diameterofeach seedling was 4.0 mm,the fresh weight and dry weightofone hundred seedlings were respectively 36.6 and 6.6 g,so the quality of seedlings was good.The sowing specification of each plot was 16.7 cm×16.7 cm,each cluster had four plants.The agronomic traits and economic characters of each growth period were examined and recorded.The harvest date were on July 21,the rice grains of each plot were harvested and dried independently,and then the yield of each plot was measured.

Starting from June 15,the continuous rainy days of Fenghua lasted 21 d during the Meiyu period;the average temperature in late June was only 22.6℃,which was the lowest in 20 years, and hours of sunshine were also the lowestsince the related statistics; rainy and sunless weather also dominated almost in early and middle July, the meteorologicalconditionswere worse than normal years.Thus the later booting stage and the heading and flowering period of early rice were affected by low temperature,sunlight shortage and more rainfall,so the pollination and seed setting was universally poor,the seed setting percentage dramatically reduced,and 1 000-seed weight was the lowest compared with normal years[3].

The experimental data were analyzed using data processing system (DPS)and EXCEL.

Results and Analyses

Yield

As shown in Table 2,with the increase of nitrogen application rate,the real cut yield of Yongxian 975 first decreased slightly and then increased slightly,the average yield per unit area of treatment①was the highest,which increased by 42.2%than nitrogen free zone;followed by treatment⑤,whose yield increased by 37.6%than nitrogen free zone,and decreased by 3.2% than treatment①,the yield-decreasing effect was not significant;the average yield per unit area of treatment②, treatment③and treatment④respectively decreased by 0.5%,1.3%and 3.6%than treatment⑤,the yield-decreasing effect was not significant. Therefore,the yield-increasing effect of each treatment was significant at the level of 0.01 compared with nitrogen free zone,applying nitrogenous fertilizer was very effective,but the treatment with different nitrogen application rates had not significant differences,the application of 150.0 kg/hm2pure nitrogen in high soil fertility was the best.

The effect of nitrogen application rate on the rate of output and economic benefit

The output rate of fertilizer refersto the productivity effect and ecological environment of food,on the basis of high and stable yield,nitrogenous fertilizer should be applied appropriately and slightly to avoid the negative effect of excess fertilization on the environment,thereby achieving the balance between cost saving and yield increasing.As seen in Table 3,the yield of 5 treatments increased obviously compared with the CK;the output rate of pure fertilizer of treatment⑤ was 12.9 kg,which was the highest,but that of treatment①was relatively lower;for economic benefit,the net earning of treatment① was the highest, namely 5 523.0 yuan/hm2;followed by treatment⑤ ,whosenetearning was 5 379.0 yuan/hm2,all these were higher than that of other treatments. From these,it was obviously seen that although the earning of 270.0 kg/hm2pure nitrogen was the best,the fertilizer was the highest,the nitrogen use efficiency was lower,and the environmental pollution and planting risk were great;while applying 150.0 kg/hm2pure nitrogen,the nitrogen use efficiency was the highest,the yield was higher,and the economic and ecological benefits were good.

Table 3 The relationship between the rate of output,economic benefit and nitrogen application rate

Table 4 Effects of different nitrogen fertilizer treatments on economic characters of Yongxian 975

The effect of nitrogen application rate on the yield from the structure of grain and panicle

From Table 4,it was shown that the setting percentage of no nitrogen treatment was the highest,namely 69.4%,the setting percentage of each treatment decreased with the increase ofnitrogen fertilizer;fortreatment groups,that under treatment⑤ was 59.9%,which ranked the first,and respectively significantly improved by 4.4,4.7 and 5.4 percentage points than treatment④,treatment③ and treatment②,as well as improved significantly at the level of 0.01 compared with treatment①,in detail,it was higher than treatment①by 8.6 percentage points.Therefore,applying nitrogenous fertilizer could lower the setting percentage of Yongxian 975;when applying 150.0 kg/hm2pure nitrogen, the setting percentage of each treatment was the highest,and it was easier to achieve high and stable yield.

Effective panicles of treatment①wasthe highest,namely406.5× 104/hm2,which improved significantly at the level of 0.01 than other treatments.Filled grains per panicle under no nitrogen treatment were the highest,followed by treatment③,and that of treatment①was the lowest.1 000-seed weight of treatment① was the highest,which improved significantly compared with treatment⑤,however, it had not significant difference with othertreatments.From theoretical yield,the yield perunitarea of treatment③was the highest,namely 8 080.1 kg/hm2,which improved 7.2% compared with treatment⑤ whose yield was 7 535.2 kg/hm2,thus the yield-increasing effect was significant, but the yield-increasing effect was not significant compared with other nitrogen application treatments,this was not totally the same as the trend of theoretical yield of each treatment;this may be connected to the effect of disastrous climate of each treatment in heading flowering period and filling stage,causing the levels of setting percentage and 1 000-seed weight below the normal level of normal years, and the yield advantage could not be exerted.Based on this,the yield increase of high nitrogen zone(treatment① and②)than low nitrogen zone(treatment④and⑤)depended on the improvement of effective pani-cles,the yield increase of medium nitrogen zone (treatment③ )was based on the improvement of effective panicles and filled grains per panicle while 1 000-seed did not decrease,that is,the panicle,grain and weight of Yongxian 975 were more coordinated when applying 210.0 kg/hm2pure nitrogen.

Conclusions and Discussions

The researches showed that panicle,grain and weight of treatment③were more coordinated and yield-increasing potential was great;the real cut yield of treatment①was the highest,and the earning was also the best, but the nitrogen use efficiency was lower,what’s more,excessive nitrogen fertilizer may cause the overgrowth,unfavorable-delayed senescence,severer plant diseases and insect pests,greater lodging risk and heavier ecological burden;the fertilizer application of treatment⑤ was the least,but its utilization rate of fertilizer was the highest,the yield was also the highest,and the economic benefit was good.With comprehensively considering the high and stable yield and the efficiency,the best quantity of pure nitrogen application on Yongxian 975 was about 150.0 kg/hm2when the field fertility was high;the quantity of pure nitrogen could be increased to 180.0 kg/hm2when the field fertility was moderate or low;in order to explore its high-yield potential,the quantity of nitrogen fertilizer could be increased to 210.0 kg/hm2in the high-yield tackling field.

The previous studies about nitrogen fertilizer showed that the optimum pure nitrogen amounts of Yongxian 15[2]and Yongxian 69[1]were respectively about 180.0 and 210.0 kg/hm2, which was greatly higher than that of Yongxian 975 whose optimum pure nitrogen amount was 150.0 kg/hm2. Therefore, in field production, to achieve high and stable yield,and improve the cost-saving effect obviously in the field production,urea application for Yongxian 975 was respectively less than that for Yongxian 15 and Yongxian 69 by 60 and 120 kg/hm2.

[1]JIN LC(金林灿),CHENG LP(成丽萍), SHI XB(施贤波),et al.Study on the optimum N application rates and N application method of rice variety Yongxian 69(早稻品种甬籼69的氮肥用量与施用方法试验)[J].Journal of Zhejiang Agricultural Sciences(浙江农业科学),2009 (2):320-321.

[2]CHENG LP(成丽萍),JIN LC(金林灿). Experiment of nitrogen fertilizer application amount and methods for early indica rice-Yongxian 15(早籼稻甬籼15氮肥施用量及施用方法试验)[J].Journal of Zhejiang Agricultural Sciences(浙江农业科学),2010(1):79-81.

[3]ZHANG H(张寒),LOU WP(娄伟平). Analysis on the effect of climatic variation on setting percentage of early season rice in recent 20 years (近20年气候变化对早稻结实率的影响分析)[J]. Journal of Zhejiang Meteorology(浙江气象),2005,26(2):26-28.

Responsible editor:Nanling WANG

Responsible proofreader:Xiaoyan WU

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早稻新品种甬籼975氮肥施用量的研究

金林灿1*,施贤波1,黄涛2,王飞军2
（1.宁波市农业科学研究院，浙江宁波 315040；2.奉化市农业技术服务总站，浙江奉化 315500）

[目的]研究甬籼975最佳氮肥施用量。[方法]设5个氮肥施用量处理和1个空白对照，小区净面积13.4 m2，3次重复，随机区组排列。[结果]各施氮处理间产量无显著差异；施纯氮210.0 kg/hm2时穗、粒、重较为协调，增产潜力大；施纯氮270.0 kg/hm2时实割产量最高，收益最好，但其肥料利用率较差，同时病虫害和倒伏风险加大，生态负担重；施纯氮150.0 kg/hm2时肥料利用率最高，产量高，经济效益好。[结论]综合考虑高产、稳产、效益，在高肥力大田中甬籼975纯氮施用量控制在150.0 kg/hm2左右为佳；当大田肥力中等或偏低时纯氮施用量可增至180.0 kg/hm2左右；为发掘其高产潜力，在高产攻关田纯氮施用量可增至210.0 kg/hm2左右。

早稻；甬籼975；氮肥施用量

金林灿（1963-），男，浙江余姚人，高级农艺师，从事水稻育种研究工作，E-mail：nbnky@126.com。*通讯作者。

2015-04-03

修回日期 2015-07-31

*Corresponding author.E-mail:nbnky@126.com

Received:April 3,2015 Accepted:July 31,2015