Effects of selenium on crop yield and accumulation of selenium, nutrients and other elements in paddy rice

2013 ◽  
pp. 83-85
Author(s):  
X Chen ◽  
C Wei ◽  
Z Bao ◽  
H Tian ◽  
Y Guo
Keyword(s):  
Crop Yield ◽  
Paddy Rice

scholarly journals Yield, nitrogen use efficiency and balance response to thirty-five years of fertilization in paddy rice-upland wheat cropping system

2019 ◽  
Vol 65 (No. 2) ◽  
pp. 55-62 ◽  
Author(s):  
Hu Cheng ◽  
Xia Xiange ◽  
Chen Yunfeng ◽  
Qiao Yan ◽  
Liu Donghai ◽  
...  
Keyword(s):  
Crop Yield ◽  
N Uptake ◽  
Cropping System ◽  
Mineral Fertilizer ◽  
Paddy Rice ◽  
N Use Efficiency ◽  
Soil N ◽  
N Input ◽  
Use Efficiency ◽  
N Use

Optimal soil nitrogen management is vital to crop production and environment protection. Little knowledge is available on crop yield, nitrogen uptake, use efficiency and balance in paddy rice-upland wheat cropping system of China. A thirty-five-year long-term field experiment was designed with nine treatments, including an unfertilized treatment (control), nitrogen (N), phosphorus (P), potassium (K) fertilizer, manure (M), and manure combined with mineral fertilizer treatments. Crop yield, N uptake, use efficiency, and N surplus or deficit amount were determined. The results indicated that rice, wheat yield and N uptake amount in the manure combined with mineral fertilizer treatments were higher than that in the manure alone or mineral fertilizer alone treatments. N use efficiency was the highest in the treatment with manure alone. Soil N input indicated a surplus in the mineral fertilizer in combination with manure treatment, but soil N input indicated a deficit in the control, NPK and M treatments. Considering crop yields, N use efficiency and N balance, recommended N application amount is almost 220 kg N/ha/year in the paddy rice-upland wheat cropping system. Taking into account labour and fertilizer sources, half mineral N and half organic N applications were recommended.

scholarly journals A land surface model combined with a crop growth model for paddy rice (MATCRO-Rice Ver. 1) – Part II: Model validation

2016 ◽  
Author(s):  
Yuji Masutomi ◽  
Keisuke Ono ◽  
Takahiro Takimoto ◽  
Masayoshi Mano ◽  
Atsushi Maruyama ◽  
...  
Keyword(s):  
Heat Flux ◽  
Crop Yield ◽  
Land Surface ◽  
Carbon Flux ◽  
Sensible Heat Flux ◽  
Land Surface Model ◽  
Paddy Rice ◽  
Surface Model ◽  
The Mean ◽  
Mean Square Errors

Abstract. We conducted a comprehensive validation of the simulations by MATCRO-Rice developed by Masutomi et al. (2016). In the validation, we compared simulations with observations for latent heat flux (LHF), sensible heat flux (SHF), net carbon flux, and paddy rice yield from 2003 to 2006. The observation site used for the comparison is located in Tsukuba, Japan, where inputs for running the model and outputs for the validation were fully observed. The 4-year average root mean square errors (RMSEs) between simulations and observations for LHF and SHF were 18.57 and 12.66 W m−2, respectively. These values for errors are comparable to those reported in earlier studies. The comparison of biomass growth during growing periods from 2003 to 2006 shows that the simulations were in agreement with the observations, indicating that the model can reproduce the net carbon flux well. The 4-year average RMSE for crop yield in the same period was 402.4 kg ha−1, which accounted for 7.9 % of the mean observed yields. These results indicate that MATCRO-Rice has high ability to accurately and consistently simulate LHF, SHF, net carbon flux, and crop yield.

scholarly journals A land surface model combined with a crop growth model for paddy rice (MATCRO-Rice v. 1) – Part 2: Model validation

2016 ◽  
Vol 9 (11) ◽  
pp. 4155-4167 ◽  
Author(s):  
Yuji Masutomi ◽  
Keisuke Ono ◽  
Takahiro Takimoto ◽  
Masayoshi Mano ◽  
Atsushi Maruyama ◽  
...  
Keyword(s):  
Heat Flux ◽  
Crop Yield ◽  
Land Surface ◽  
Crop Yields ◽  
Sensible Heat Flux ◽  
Paddy Rice ◽  
Surface Model ◽  
Model Parameters ◽  
Carbon Uptake ◽  
Mean Square Errors

Abstract. We conducted two types of validation for the simulations by MATCRO-Rice developed by Masutomi et al. (2016). In the first validation, we compared simulations with observations for latent heat flux (LHF), sensible heat flux (SHF), net carbon uptake by crop, and paddy rice yield from 2003 to 2006 at the site where model parameters are parameterized. In the second validation, we compared the observed and simulated paddy rice yields over Japan from 1991 to 2010 between observations and simulations. The 4-year average root mean square errors (RMSEs) of the first validation for LHF and SHF were 18.20 and 15.47 W m−2, respectively. These values for errors are comparable to those reported in earlier studies. The comparison of biomass growth during growing periods from 2003 to 2006 at the parameterization site shows that the simulations were in agreement with the observations, indicating that the model can reproduce the net carbon uptake by crops well. The 4-year average RMSE of the first validation for crop yield in the same period was 410.6 kg ha−1, which accounted for 8.1 % of the mean observed yields. The error of the second validation for crop yield was 16.7 % and the correlation of crop yields between observations and simulations from 1991 to 2010 was significant at 0.663 (P < 0.01). These results indicate that MATCRO-Rice has high ability to accurately and consistently simulate LHF, SHF, net carbon uptake by crop, and crop yield.

K-MEANS CLUSTERING ALGORITHM BASED CLASSIFICATION OF SOIL FERTILITY IN NORTH WEST NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 780-787
Author(s):  
Ibrahim Hassan Hayatu ◽  
Abdullahi Mohammed ◽  
Barroon Ahmad Isma’eel ◽  
Sahabi Yusuf Ali
Keyword(s):  
Soil Fertility ◽  
Crop Yield ◽  
Clustering Algorithm ◽  
Soil Samples ◽  
North West ◽  
R Programming ◽  
Available Information ◽  
Northwest Region ◽  
The Relationship

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production.  Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.

Evaluation of nitrogen dynamics and crop yield in a long-term tillage experiment

2007 ◽  
Vol 35 (2) ◽  
pp. 769-772 ◽  
Author(s):  
Attila Megyes ◽  
Tamás Rátonyi ◽  
Dénes Sulyok
Keyword(s):  
Crop Yield ◽  
Nitrogen Dynamics
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