Nitrogen fertilizer and wheat in a semi-arid environment. 2. Climatic factors affecting response

1968 ◽  
Vol 8 (31) ◽  
pp. 223 ◽  
Author(s):  
JS Russell

The response of Gabo wheat to nitrogen fertilizer at 52 sites in the wheat growing areas of South Australia during 1956-61 was examined in relation to climatic factors by a stepwise multiple regression analysis using a computer. The ten dependent variables were the linear and quadratic coefficients obtained by fitting orthogonal polynomials to response curves of various parameters (grain yield, grain + straw yield, harvest index, grain nitrogen percentage, and grain nitrogen yield) to applied nitrogen at each of the 52 sites. The 23 independent variables were the amounts of rainfall and evaporation during the growing period, maximum and minimum temperatures and estimates of high temperature stress during spring and amount of rainfall immediately after sowing at each site. The climatic variables examined explained 46.5, 64.3, and 64.3 per cent of the variation in the response to nitrogen fertilizer of grain yield, grain + straw yield, and grain nitrogen yield respectively. The positive effects of increasing amounts of winter rainfall on yield response to applied nitrogen were marked. On the other hand, the negative effects of high maximum temperatures in the latter part of the growing period, particularly during October, on yield response were also evident.

1968 ◽  
Vol 8 (32) ◽  
pp. 340 ◽  
Author(s):  
JS Russell

The response of Gabo wheat to applied nitrogen at 52 sites in the wheat growing areas of South Australia during 1956-61 was examined in relation to soil and cultural factors, as separate groups and together with climatic factors, by a stepwise multiple regression analysis using a computer. The 10 dependent variables were the linear and quadratic coefficients obtained by fitting orthogonal polynomials to response curves of various parameters (grain yield, grain + straw yield, harvest index, grain nitrogen percentage, and grain nitrogen yield) to applied nitrogen at each of 52 sites. The independent variables were 14 soil properties, such as total nitrogen content and initial nitrate status, and 6 cultural characteristics, including date of sowing and period of cultivation. In addition, 23 climatic variables were also included in analysis considering all independent variables. Of the soil variables the most potent was initial nitrate content of the 0-6 inch horizon. Date of sowing was the most potent cultural variable. The proportion of variance explained in the final analysis by the variables examined was greatest for grain nitrogen yield (73.0 per cent) and grain + straw yield (72.1 per cent). The value for grain yield was 48.9 per cent. Differences between nitrogen and phosphorus response in a semi-arid environment and the theoretical and practical implications of these differences are discussed in relation to the predictive value of soil analyses.


1964 ◽  
Vol 4 (15) ◽  
pp. 345 ◽  
Author(s):  
JS Russell

The effect of nitrogen fertilizer applied at seeding on the nitrogen content of wheat grain was studied in 63 experiments during the six seasons 1956-1961. The overall effect of fertilizer was to increase grain nitrogen percentage, but there were situations where no change and even decreases in grain nitrogen percentage were found. The magnitude of the changes due to nitrogen fertilizer was small in relation to change brought about by climatic factors. Both the change in nitrogen content and nitrogen yield from applied fertilizer showed a relation to the nitrogen content of grain from unfertilized plants. Significant differences between varieties were found for nitrogen yield response but not for nitrogen content response.


1968 ◽  
Vol 8 (35) ◽  
pp. 736 ◽  
Author(s):  
JS Russell

The difficulties in predicting grain yield response to applied nitrogen under conditions of low and variable rainfall are discussed. Three models of grain yield response to applied nitrogen fertilizer for each of two strategies are proposed, based on data from field experiments carried out in the wheat growing areas of South Australia. In the first strategy (nitrogen applied at sowing) the parameters are May-August rainfall, October mean maximum temperature and one of three alternative site criteria, initial soil nitrate content (0-6 inches sampled shortly before sowing), 15-atmospheres soil moisture percentage (0-6 inches), or estimated nitrogen status. In the second strategy (nitrogen applied in late winter) the parameters are similar, except that May-July rainfall replaced May-August rainfall and a statistical relationship between yield response due to late application as compared with application at sowing was used. The response surfaces were examined using a calculated most profitable rate of application with a range of grain : fertilizer price ratios from 2 to 8. These calculations emphasize the importance of economic factors in affecting fertilizer use in areas where responses are small and variable. The limitations of the models and problems associated with the use of predicted climatic criteria are discussed. There is a need for further studies to iteratively test and modify these empirical models and ultimately to develop mechanistic models. Further study is also suggested on field aspects of late application and the possible role of both plant analysis and the single ion nitrate electrode for site characterization.


1963 ◽  
Vol 3 (11) ◽  
pp. 319 ◽  
Author(s):  
JS Russell

Examination of results from a large number of experiments in the wheat growing areas of South Australia has shown a relation between grain yield response to nitrogen fertilizer and both grain nitrogen percentage and the ratio. (Yield of grain)/(Amount of nitrogen in grain and straw) of corresponding unfertilized wheat plants. With Gabo, large yield responses to nitrogen fertilizer were associated with grain nitrogen percentages of less than 2.0 per cent N (9.9 per cent protein). Above 2.3 per cent N (11.3 per cent protein) positive responses to nitrogen were small and some negative responses were found. Similar overall trend were shorn by Insignia 49, Sabre and Quadrat. Exponential regression equations were calculated for Gabo allowing prediction of grain yield response at rates up to 46 lb fertilizer N an acre under conditions which result in grain protein contents of 7.5 to 16 per cent. Most profitable rates of nitrogen fertilizer application were also calculated for several different fertilizer-grain price levels. Possible value of the nitrogen content of wheat grain in the selection of regions, soil types, and cultural practices where nitrogen fertilizer may be used is discussed.


1987 ◽  
Vol 38 (4) ◽  
pp. 681 ◽  
Author(s):  
AS Hodgson ◽  
DA MacLeod

Foliar-applied nitrogen (N) fertilizer was investigated as a means of ameliorating the damage to cotton of waterlogging associated with extended furrow irrigation of a cracking grey clay. Dissolved urea was applied at 0, 5, 10 and 20 kg N ha-1 to the cotton foliage one day before furrow irrigations lasting 4, 8, 16 and 32 h. Treatments were repeated at three crop irrigations. Storms following the first two irrigations delayed the recovery from waterlogging and reduced treatment differences. However, foliar-applied N significantly increased late square and green boll numbers after the third irrigation, and produced more open bolls and heavier lint yields than the control treatment at harvest. Lint yields increased by 2.8, 5.9, 8.4 and up to 10.5 kg ha-1 per kg of foliar N applied before irrigations lasting 4, 8, 16 and 32 h, respectively. From this interaction it was concluded that foliar-applied N ameliorated the effects of waterlogging. Nevertheless, in the most severe waterlogging treatment, yield response to foliar N reached a limit, indicating that some other factor had become limiting.


1984 ◽  
Vol 24 (125) ◽  
pp. 250 ◽  
Author(s):  
PE Bacon ◽  
DP Heenan

The growth, nitrogen use and yield of rice cv. lnga were examined in three experiments in 1978, 1979 and 1980. In each experiment, one rate of nitrogen was applied at six different times between permanent flood and three weeks after panicle initiation. Application of 50 kg N/ha in 1978 and 70 kg N/ha in 1980 at permanent flood increased yield. A higher rate (100 kg N/ha) at permanent flood in 1979 greatly increased vegetative growth but had little effect on grain yield. The grain yield response to 100 kg N/ha in 1979 significantly increased when application was delayed until panicle initiation. Nitrogen topdressing up to 14 d after panicle initiation resulted in an increased percentage of filled florets per panicle and heavier grains compared with application 14-21 d before panicle initiation. Delaying nitrogen application till 2 1 d after panicle initiation resulted in lower numbers of florets per panicle and consequently reduced yield.


1971 ◽  
Vol 7 (1) ◽  
pp. 21-26 ◽  
Author(s):  
N. K. Jain ◽  
D. P. Maurya ◽  
H. P. Singh

SUMMARYLinear regression of grain and straw yield of dwarf wheats on level of fertilizer nitrogen was significant, but the efficiency of fertilizer nitrogen was determined by the time and method of its application. A single application as a basal dressing was the least productive for grain yield, while split fertilization at sowing and at first irrigation increased the efficiency of applied nitrogen. Further splitting in three doses did not benefit wheat. Foliar application of nitrogen to replace top dressing at the heading stage was of no advantage while replacement of a top dressing at first irrigation by urea spray at heading was definitely deleterious.


2018 ◽  
Vol 16 (1) ◽  
pp. 12-16
Author(s):  
Jyoti Adhikari ◽  
Abdur Rahman Sarkar ◽  
Md Romij Uddin ◽  
Uttam Kumer Sarker ◽  
Kawsar Hossen ◽  
...  

The research work was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during aman season from July to December 2015 to study the effect of nitrogen fertilizer and weed management on the growth and yield of transplant aman rice cv. BRRI dhan46. The experiment consisted of four fertilizer treatments viz. 0 kg N ha−1 (N0), 40 kg N ha−1(N1), 80 kg N ha−1(N2) and 120 kg N ha−1(N3) and four weeding treatments viz. one hand weeding at 20 DAT (W1), two hand weedings at 20 and 35 DAT (W2), three hand weedings at 20, 35 and 50 DAT (W3), weeding by Japanese rice weeder twice at 20 and 35 DAT (W4) and unweeded control (W5). The experiment was laid out in the randomized complete block design with three replications. The highest plant height (113.00 cm), number of total tillers hill−1 (8.74), number of effective tillers hill−1 (6.18), panicle length (21.98 cm), number of grains panicle−1 (114.20), grain yield (4.00 t ha−1), straw yield (5.25 t ha−1) and biological yield (9.25 t ha−1) were recorded in N2 (80 kg N ha−1) treatment. The lowest plant height (106.00 cm), number of total tillers hill-1 (7.20), number of effective tillers hill−1 (5.00), panicle length (20.70 cm), number of grains panicle−1 (97.60), grain yield (3.52 t ha−1), straw yield (4.46 t ha−1) and biological yield (7.97 t ha−1) were recorded from N0 (No nitrogen fertilizer control) treatment. On the other hand, the highest grain yield 4.23 t ha−1 was observed in three weedings condition because of the highest number of effective tillers hill−1 (6.81), number of grains panicle−1(111.10). The highest straw yield (5.51 t ha−1) was also found in three weeding condition. The lowest grain yield (3.40 t ha−1) was recorded in W5 (unweeded control) treatment. The lowest straw yield (4.31 t ha−1) was also observed in W5 (unweeded control) treatment because of the smallest plant (106.97 cm) and lower number of total tillers hill−1 (7.20). Therefore, 80 kg N ha−1along with three hand weedings at 20, 35 and 50 DAT may be used for obtaining the highest grain and straw yields of BRRI dhan46J. Bangladesh Agril. Univ. 16(1): 12-16, April 2018


2010 ◽  
pp. 67-76
Author(s):  
ABM Masud Hasan ◽  
Md Mizanur Rahman ◽  
MA Hashem

An experiment was conducted to study the yield response and nutrient uptake of rice (BRRI dhan30) to reduced rates of N, P and K from the recommended fertilizer doses (RFD). The experiment was laid out in a randomized complete block design with four replicates. There were ten treatments viz. T1 (control), T2 (RFD), T3 (RFD - 20% N), T4 (RFD - 40% N), T5 (RFD - 20% P), T6 (FRD - 40% P), T7 (RFD - 20% K), T8 (RFD - 40% K), T9 (RFD - 20% NPK) and T10 (RFD - 40% NPK). The recommended fertilizer doses of the crop were 100 kg N, 20 kg P, 40 kg K, 20 kg S and 3 kg Zn ha-1. The highest grain yield (5.10 t ha-1) and straw yield (7.02 t ha-1) were obtained by applying recommended doses of fertilizers which were insignificantly different from those observed in the treatments where N, P and K were reduced at the rate of 20% from the recommended doses. Similar results were also found in case of P, K and S content and uptake by rice plant, while the variation for N was found significant. Overall results indicated that 20% reduction of either N or P or K from the recommended doses would not significantly affect the yield of rice.


Sign in / Sign up

Export Citation Format

Share Document