Suying WANG ,Huifang XU,Zhiqing WU,Jinhe HU,Xihua ZENG,Qingyun XIONG,Zhenggen LI,Baoqing XU

1.Institute of Grain and Oil Crops,Nanchang Academy of Agricultural Sciences,Nanchang 330025,China;

2.Integrated Station of Agricultural Technology Generalization of Wenzhen Town in Jinxian County,Jinxian 331721,China;

3.Institute of Agricultural Sciences of Xinjian County,Xinjian 330030,China

Responsible editor:Nanling WANG Responsible proofreader:Xiaoyan WU

R ice (Oryza sativa) is the most important crop in the world.China,as the world＇s biggest producer and consumer,its production and consumption account for about 30%of the world.Rice is also the most important crop in China,whose planting area accounts for around 27% of all crops and production accounts for about 39% of total output in China[1].However,the continuous increase of population has resulted in a sharp decrease of the per capita arable land area in China,therefore,how to solve food problems is particularly prominent.Raising the per unit yield is the only way to increase total rice yield[2-3].Increasing fertilizer is an important condition for high-yielding cultivation of rice,with the continuous improvement of rice yield level,fertilizer application rate is also gradually increased,but excessive fertilizer application will drop the utilization of nutrient absorption,and cause environmental pollution.

With the rapid development of science and technology as well as production technology,trace-element nutrient fluid has been accepted by people gradually,the report on production increase of rice,wheat,corn,fruit and vegetable,etc.by nutrient fluid has become more[4].But the study of the effect of soaking liquid on rice yield has been reported rarely.The paper studied the effect of "Yonghao" liquid fertilizer on rice yield,to provide basis for the use of soaking liquid in rice production.

Materials and Methods

Experimental design

The experiment was carried out in Wenzhen Town of Jinxian County from March to July in 2013,the physicochemical properties of the tested soil were as follows:pH 6.02,3.82 g/kg organic matter,1.78 g/kg total N,197 mg/kg available nitrogen,24.4 mg/kg P2O5,and 107.5 mg/kg K2O.The tested variety of rice was Rongyou 463,the sowing and transplanting dates were March 25 and April 26,respectively,and the planting specification was 20 cm×16.7 cm.

The experiment had 3 treatments.T1:conventional seed soaking method,"Hengda" Prochloraz purchased from the market was used following the product instruction.T2:using "Yonghao" liquid fertilizer soaking,the soaking liquid was provided by Jiangxi Yonghao Biotechnology Co.,Ltd.The liquid was made by combining low deuterium and microcluster water with fulvic acid,quantitative N,P and K,which was only used for soaking humic acid liquid,the using method was:soaking seed using soaking liquid directly,liquid level was 2 cm higher than seed.T3:soaking seed using clean water (CK).The soaking time of the three treatments was 36 h.

In the experiment,randomized block design was used with three repetitions for each sample,the area of each group was 25 m2,and fertilizer water of each treatment was the same,the usage of N,P and K2O were 180,90,150 kg/hm2,respectively,in which N fertilizer was composed by base fertilizer:tiller fertilizer:panicle fertilizer=5:2:3,and K fertilizer was made by base fertilizer:panicle fertilizer=7:3.

Measured indexes and methods

Germination rate,emergence rate,seedling rate of seedsAfter soaking seeds,100 seeds were chosen randomly for each treatment to culture in 25 ℃constant temperature oven,then the number of germination seeds within 7 days was recorded,and the percentage in all tested seeds was calculated.In rice seedling bed,1 000 seeds were sown,and the emergence rate of rice and the seedling rate after transplanting were investigated accordingly with three repetitions.

Seedling quality100 rice seedlings were selected when transplanting rice,to investigate seedling height,leaf age,stem diameter,the leaves number per plant,tillers per plant,white root number,and root length.

Chlorophyll contentThe content of chlorophyll was determined by chlorophyll meter at rice tillering stage,panicle primordium differentiation stage and heading period.

Tiller dynamicsAfter transplanting rice,20 plants for each plot were chosen,and the tillering rate per 5 d was recorded until heading period.

Yield and yield componentDuring mature period,the actual output of each plot was measured,and sample survey of each treatment on effective panicle number,grain number per spike,filled grain rate and 1 000-grain weight was carried out.5 plants during mature period of each treatment were selected to record effective panicle number,grain number per spike,filled grain rate and 1 000 grain weight.

Results and Analyses

Effects of different treatments on germination rate,emergence rate,seedling rate of rice

As seen in Table1,rice germination rate of three treatments was the same,rice emergence rate and seedling rate of T1 were higher than others,rice seedling rate of T2 was higher than CK treatment,which indicated that drug soaking and "Yonghao" liquid fertilizer soaking can improve rice seedling rate.

Effects of different treatments on the seedling quality and growth dynamics of rice

From Table2,we drew the conclusion that rice of T2 group was obviously better than others in the aspects of seedling height,leaf age,stem diameter,tiller number,white root number and average white root length,among which seedling height increased 22.45%and 17.10%of T1 and CK,respectively,and stem diameter increased 47.27% and 32.87% of T1 and CK,respectively.Therefore,using"Yonghao" liquid fertilizer soaking can cultivate strong seedlings,make seeds sprout early and root growth ability become strong,which were beneficial to the formation of high-yield group.

As shown in Fig.1,the tiller number of each treatment showed increasing trend during 30 d after transplanting,and the difference of each treatment was not obvious.After 30 d,the tiller number decreased gradually,and the tiller number of T2 treatment was higher than that of T1 and CK,the tiller number between T1 and CK had no obvious difference.

As seen in Table3,SPAD value of rice leaves in heading period was the highest,and T2 was the highest group in every growth stage.At the peak time of tiller stage,T1’s SPAD value was the lowest,in the heading period and 15 d after heading,SPAD of CK group was the lowest.15 d after rice tiller stage,SPAD of T2 group increased 1.95% and 3.85% of T1 and CK,respectively.Thus,"Yonghao" liquid fertilizer soaking can improvechlorophyll content of rice leaves,then may influence rice yield.

Table1 Effects of different seed presoaking treatments on germination rate,emergence rate,seedling rate of rice %

Table2 Effects of different seed presoaking treatments on the seedling quality of rice

Table3 Effects of different seed presoaking treatments on SPAD values of rice leaves

Table4 Effects of different seed presoaking treatments on rice yield and yield component

Effects of different treatments on rice yield and yield component

As shown in Table4,T2 group’s rice yield was the highest and increased 8.02% and 9.82% of T1 and CK,respectively;the following was T1,which increased 1.66% comparing with CK.In yield component,the difference of effective panicle number of each treatment reached a very significant level,and T2 was the highest,compared with T1 and CK groups,it increased 5.34%and 12.79%,respectively; the second was T1,which increased 6.98% of CK.For the number of grain per ear and seed setting rate of each treatment,the rank was T2 ＞T1 ＞CK,and the difference of each treatment was not significant.The rank of 1 000-grain weight was T2 ＞CK＞T1.In mature period,T2 group’s dry matter accumulation was the highest,but the difference of each treatment was not significant.

In sum,using "Yonghao" liquid fertilizer soaking was the best method for high-yielding rice,which mainly expressed in the increase of effective panicle number,filled grain rate and 1 000-grain weight.Drug soaking also can improve rice yield,which mainly by reducing disease incidence of rice.

Conclusions and Discussions

The experiment showed that rice treated by "Yonghao" liquid fertilizer soaking was obviously better than others in the aspects of seedling height,leaf age,stem diameter,tiller number,white root number and root length,therefore,using"Yonghao"liquid fertilizer soaking can cultivate strong seedlings,make seeds sprout early and root growth ability become strong,which were beneficial to the formation of high-yield group.

The content of chlorophyll in rice leaves was related to photosynthetic rate and crop growth rate[5-6].Some studies suggested that chlorophyll content had a positive correlation with photosynthetic rate within certain limits[7-8].Liu Yanzhuo et al.[9]measured 5 high-yielding rice varieties (combinations) in the aspects of saturated photosynthetic rate and chlorophyll content of flag leaves from late growth stage to full ripe stage,and the results showed that chlorophyll content of flag leaves kept in a higher level in the formative and filling stages of economy organs,which can generate higher photosynthetic rate of rice leaves,all those were related to rice yield.

The research showed that SPAD value of rice leaves in heading period was the highest,and T2 was the highest group in every growth stage,this may affect rice yield by affecting rice photosynthesis,indicating that using"Yonghao" liquid fertilizer soaking was the best method for high-yielding rice,which mainly expressed in the increase of effective panicle number,filled grain rate and 1 000-grain weight.Drug soaking also can improve rice yield,which mainly by reducing disease incidence of rice.

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