Effects of source and amount of fertilizer nitrogen and nitrification inhibitors on the yield and nitrate concentration of glasshouse lettuce

1985 ◽  
Vol 1 (3) ◽  
pp. 80-81 ◽  
Author(s):  
J. Vaughan
1970 ◽  
Vol 75 (3) ◽  
pp. 375-379 ◽  
Author(s):  
B. A. Lakhdive ◽  
Rajendra Prasad

SUMMARYTwo varieties of irrigated rice N.P. 130 (a tall variety) and Taichung Native-1 (a dwarf variety of indica rice) were compared in 1966 and 1967 when grown with several amounts of sodium nitrate and ammonium sulphate. Comparisons of ammonium sulphate treated with ‘N-Serve’ or with ‘AM’ against untreated ammonium sulphate were made.Applying more than 60–80 kg N/ha did not increase the number of panicles per m with N.P. 130 but lowered the number of spikelets and filled grain percentage. Up to 120 kg N/ha, panicle number and the number of spikelets of Taichung Native-1 increased significantly but the filled grain percentage was not increased; yield of grain responded significantly up to 120 kg N/ha. Taichung Native-1 yielded more grain and less straw than N.P. 130. Increasing the nitrogen applied significantly increased the yield of straw from both varieties.Ammonium sulphate increased panicle number and reduced the percentage of filled grain compared to sodium nitrate but the increase in panicle number was higher with Taichung Native-1 than with N.P. 130; as a result ammonium sulphate consistently increased the grain yield of Taichung Native-1. When the ammonium sulphate was treated with either inhibitor it gave more grain of Taichung Native-1 than untreated fertilizer; treated fertilizer gave more straw of both varieties.


1993 ◽  
Vol 34 (1) ◽  
pp. 37-44 ◽  
Author(s):  
J. R. Freney ◽  
D. L. Chen ◽  
A. R. Mosier ◽  
I. J. Rochester ◽  
G. A. Constable ◽  
...  

2019 ◽  
Author(s):  
Chem Int

Mathematical model was developed and evaluated to monitor and predict the groundwater characteristics of Trans-amadi region in Port Harcourt City. In this research three major components were considered such as chloride, total iron and nitrate concentration as well as the polynomial expression on the behavious on the concentration of each component was determined in terms of the equation of the best fit as well as the square root of the curve. The relationship between nitrate and distance traveled by Nitrate concentration by the model is given as Pc = 0.003x2 - 0.451x + 14.91with coefficient of determination, R² = 0.947, Chloride given as Pc = 0.000x2 - 0.071x + 2.343, R² = 0.951while that of Total Iron is given as Pc = 2E-05x2 - 0.003x + 0.110, R² = 0.930. All these show a strong relationship as established by Polynomial Regression Model. The finite element techniques are found useful in monitoring, predicting and simulating groundwater characteristics of Trans-amadi as well as the prediction on the variation on the parameters of groundwater with variation in time.


2010 ◽  
Vol 18 (4) ◽  
pp. 683-688 ◽  
Author(s):  
Chao ZHANG ◽  
Yu-Ping CHE ◽  
Zhong-Pei LI

2003 ◽  
Vol 67 (3) ◽  
pp. 937-947 ◽  
Author(s):  
R. B. Ferguson ◽  
R. M. Lark ◽  
G. P. Slater

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