Soil Analysis
The result of the soil sample before planting of physical and chemical analysis of the site was done in Mekelle soil laboratory. The soil of the experimental site has a proportion of 30% sand, 56% silt and 14% clay and it is classified as silt loam soil according the soil triangle texturally (Table 1). The organic carbon content of the soil was 0.8% which rated under low, in agreement with the finding of (Tekalign, 1991). The pH valve of the soil result at the experimental site 7.4 was almost neutral. The cation exchange capacity was 35.4 Meq/100 gm soil which is categorized as medium.
The results in (Table 2) indicated that the soil comprised total N of 0.121% and thus the composite soil sample of the experimental area was rated as low (London, 1991). The available P in the experimental soil contains 8.46 ppm. According Olson et al(1954), it has medium level of available P in the experimental site. This is may be due to the cropping history of the area was maize so, maize is not required in as high amounts as N.
Table 1
Some Physio-chemical properties of the soil at the experimental field before sowing
Properties | Values | Method code | Remark |
Soil physical properties | | | |
Sand (%) | 30 | MSL-M7.02-8 | |
Clay (%) | 14 | MSL-M7.02-8 | |
Silt (%) | 56 | MSL-M7.02-8 | |
Soil texture | | | Silt Loam |
Soil chemical properties | | | |
Organic carbon (%) | 0.28 | MSL-M7.02-8 | Low |
pH (by 1:2.5 soil water ratio) | 7.4 | MSL-M7.02-5 | Almost neutral |
Cation exchange capacity Meq/100 gm soil | 35.4 | MSL-M7.02-8 | Low |
Total nitrogen (%) | 0.121 | MSL-M7.02-8 | Low |
Available phosphorus (ppm) | 8.46 | MSL-M7.02-8 | Medium |
Mekelle soil laboratory (2019) |
Phenology And Growth Parameters
Phenology traits
The analysis of variance for days to tasseling and silking maize crop was not significantly affected by fertilization of blended fertilizer doses (Table 2).Mostly those fertilizer expected to have encouraged early establishment, rapid growth and development of the crop thus; shortening the days to tasseling, silking and maturity but the current result were revealed the reverse. This may be due to application of N fertilizer treatment to all treatments at the same rate of blended fertilizer and thus effect of N was insignificant. This work is similarly reported by Tekulu et al (2019) 50% of tasseling, silking and 90% maturity was not affected by the blended fertilizer treatments. This result is unlike the work of Bakala (2018) found that 50% tasseling, silking and maturity to be significantly affected by the application of blended fertilizer rates.
Growth Parameter
Plant height
Analysis of the variance showed that, there was a significant difference (p ≤ 0.05) among the fertilizer rates on maize height. Application of blended fertilizer significantly increase plant height as compare to the control and lower rates. The heights plant height 230.5 cm, 228 cm and 227 cm was recorded from 250 and 200 kg ha-1 NPSZnB and 200 kg ha-1 DAP. This increment in plant height might be due to increase in cell elongation and more vegetative growth attributed to different nutrient content of micronutrients. Thus the result indicated that blended fertilizers application has enhanced the maize vegetative growth. On the other hand the minimum plant height in unfertilized and low level plots might have been due to low soil fertility level in the study area. This result is in agreement with that of Tekle and Wassie (2018) who found that application of blended fertilizers which significantly increased plant height as compared to the control.
Table 2
Effect blended fertilizer (NPSZnB) rates on yield and yield components of maize
Treatment (kg ha -1) | Two years combined result |
Days to 50% tasseling | Days to 50% silking | Days to 90% maturity | plant height (cm) | N cobs PP | Ear length |
0 | 86 | 89.7 | 135.5 | 190.3d | 1.03 | 13.4c |
50 kg ha-1 NPSZnB | 86 | 90 | 136.3 | 191d | 1 | 13.5c |
100 kg ha-1 NPSZnB | 86 | 89.5 | 136.3 | 219.6c | 1.1 | 14.2b |
150 kg ha-1 NPSZnB | 84.7 | 89 | 136.2 | 222bc | 1 | 15.4a |
200 kg ha-1 NPSZnB | 84.7 | 88.3 | 136.7 | 228ab | 1.03 | 15.2a |
250 kg ha-1 NPSZnB | 83.3 | 88 | 136.3 | 230.5a | 1.03 | 15.4a |
200 kg ha-1 DAP | 82.7 | 87.3 | 136 | 227abc | 1.03 | 15.3a |
Mean | 84.6 | 88.8 | 136.2 | 206.5 | 1.03 | 14.6 |
LSD(0.05) | NS | NS | NS | 215.5 | NS | 0.45 |
CV (%) | 2.5 | 1.6 | 1.44 | 2.22 | 5.5 | 1.8 |
Where P = kg ha-1 Zn = g/L, LSD (0.05) = Least Significant Difference at 5% level; CV = Coefficient of variation, NS = Non significant, Means connected by the same letter are not different from each other at 5% level of significance |
Yield-related Parameters
Number of Cobs per Plant and Number of Seed Rows per Cob
Analysis of variance of blended fertilizer treatments on number of cobs per plants and number of seed rows per cob did not show significant difference (p ≤ 0.05).Unlike the work of Chimdessa (2016) application of blended fertilizer increased number of cobs and number of seed rows per cob over the control
Ear Length
Analysis of variance indicated that there is a significant effect between the blended fertilizer rates on maize ear length (p ≤ 0.05). The ear length increment with the blended fertilizer application might be attributed to good photo assimilate supply of the blended elements. The highest ear length was recorded from the 100–250 kg of NPSZnB ha -1
Number Of Seeds Per Row
Result of the analysis of variance (p ≤ 0.05) revealed blended fertilizer rates have a significant effect on number of seeds per row. The highest number of seeds per row (35.5) was achieved from the treatments 150 kg NPSZnB ha− 1. On the other hand the similar number of seeds per row (30.8) was recorded from untreated plot(control)..These increments of number of seeds per row with the blended fertilizer could be due to the more plant nutrient contents of blended fertilizer. In agreement with result of this experiment,maize production depends mainly on the availability of essential plant nutrients and application of fertilizers (Adediran, 2003).
Table 3
Effect blended fertilizer NPSZnB rates on yield and yield components of maize
Treatment (kg ha -1) | Two years combined result |
Number of seed rows/cob | Number of seeds /row) | Grain yield (kg ha-1) | Biomass yield (kg ha-1) | 1000 seed weight (gm) | Harvest index |
0 | 13.9 | 30.8d | 5667c | 15314d | 328.58 | 0.357bc |
50 kg ha-1 NPSZnB | 13.8 | 31.4 cd | 5687c | 14927d | 336.33 | 0.38a |
100 kg ha-1 NPSZnB | 13.7 | 33.2bc | 6031b | 16388.4c | 331.58 | 0.38a |
150 kg ha-1 NPSZnB | 14.5 | 35.5a | 6666a | 18237ab | 341.42 | 0.37a |
200 kg ha-1 NPSZnB | 13.9 | 34.7ab | 6447a | 18131ab | 339.75 | 0.355bc |
250 kg ha-1 NPSZnB | 13.8 | 33.8ab | 6526a | 19141 a | 333.67 | 0.34c |
200 kg ha-1 DAP | 13.5 | 32.5bc | 6551a | 18737.4 a | 343.92 | 0.349bc |
Mean | 13.8 | 33.2 | 6225 | 17254.7 | 336.5 | 0.36 |
LSD(0.05) | NS | 2.12 | 271 | 1015.9 | NS | 0.021 |
CV (%) | 4.9 | 3.7 | 2.5 | 3.4 | 3.3 | 3.2 |
Where P = kg ha-1 Zn = g/L, LSD (0.05) = Least Significant Difference at 5% level; CV = Coefficient of variation, NS = Non significant, Means connected by the same letter are not different from each other at 5% level of significance |
Grain Yield
The application of different rate of blended fertilizer showed a highly significant (< 0.001) effect on grain yield of maize. The highest grain yield recorded from the application of (150 to 250 kg ha-1 NPSZnB and 200 kg ha-1) DAP did not have statically deference each other. But they have a highly significance deference from the other treatments. Whereas, the lowest grain yield was recorded from plots treated with zero (5667 kg ha− 1) and 50 kg ha-1 (5687 kg ha-1) NPSZnB fertilizers. The grain yield increment may be beneficial effect of yield contributing character and positive interaction of nutrients in the blended fertilizers. This result in agreement with the current findings Tekle and Wassie (2018) found that grain yield of tef was found highest in blended fertilizers as compared to control treatment and recommended NP fertilizers. Additionally, Jafer (2018) found better grain yield from application of blended fertilizer compare to recommended NP fertilizer and unfertilized plot.
Biomass Yield
Analysis of the variance showed that, there is a significant difference (P ≤ 0.001) between blended fertilizer rates on biomass yield of maize. The highest biomass yield was recorded from the treatment received the heights blended fertilizers rate of 150–250 kg NPSZnB /ha and 200 kg ha-1 DAP (Table 3) without statically difference. On the other hand the lowest biomass yields (14927 and 15314) obtained with the application of low NPSZnB fertilizer and control. The lowest biomass yields are might have been due to reduced leaf area development resulting low efficiency in the conversion of solar radiation to maintain efficient photosynthesis. When the application of blended fertilizer is increased biomass yield of maize showed increasing trend. The present results are in agreement with tekulu et al. (2019) who obtained significantly highest biomass yield of maize crop when high blended fertilizer rates applied.
Thousand Seed Weight (gm)
Thousand grain weight of maize did not show any significant variations (p < 0.05) amongst the blended fertilizer rates. This result is different from tekulu (2019) reported that thousand seeds weight of maize crop were found to be significantly affected by blended fertilizer rates compared to the control.
Harvest Index
Analysis of the result revealed that application of the blended fertilizer in compound had significant effect (P < 0.05) on harvest index of maize crop. The maximum harvest index was obtain from the application of 50 to 150 kg NPSZnB per ha as compared to the other fertilizer rates. The blended fertilizer might be attributed to positive interaction of nutrients in the blended fertilizer gives more grain weight and have positive relation to grain yield increment. This result agrees with the findings of Tekulu (2019) who reported that harvest index of maize was found to be highest at the rate of 150 kg NPSZnB per ha as weighed to the control treatment.
Nitrogen Uptake By Grain And Stalk
The results presented in (Table 4) indicated that, the highest N uptake form grain (10 kg /ha) and stover (20.67 kg /ha) was obtained in plot treated by (200 and 250 kg) NPSZnB /ha. While the lowest N uptake by grain (7.59 and 7.56 kg / ha) was recorded in control and a plot treated by the low level. The lowest N uptake by Stover (10.45 kg ha-1) was recorded from the plot treated by 50 kg NPSZnB /ha of blended fertilizer. The maximum N uptake form grain and stover are increased by 24.4 and 49.4 from the minimum uptake which treated by 50 kg ha-1 NPSZnB fertilizer. This study agreed with the findings of Jones (1996) who reported that agronomic practices affected not only yield, but also seed N contents. The highest yield was associated with highest dry matter production and Stover N uptake increased significantly with optimum nutrient application.
Table 4
The effect of blended fertilizer treatments on nutrient uptake of maize
Treatment | Nutrient uptake (Kg ha-1) |
Nitrogen | Phosphorus |
Grain | Stover | Total | Grain | Stover | Total |
Control | 7.59 | 15.93 | 23.52 | 2.27 | 18.38 | 20.64 |
50 kg ha-1 NPSZnB | 7.56 | 10.45 | 18.01 | 4.04 | 19.85 | 23.89 |
100 kg ha-1 NPSZnB | 8.89 | 13.77 | 22.66 | 5.12 | 19.67 | 24.78 |
150 kg ha-1 NPSZnB | 8.93 | 15.69 | 24.62 | 5.12 | 32.41 | 37.53 |
200 kg ha-1 NPSZnB | 10.0 | 16.32 | 26.31 | 5.09 | 33.18 | 38.27 |
250 kg ha-1 NPSZnB | 9.33 | 20.67 | 30.00 | 5.22 | 36.94 | 42.16 |
200 kg ha-1 DAP | 9.43 | 17.05 | 26.48 | 4.91\ | 45.53 | 50.45 |
Similarly, Fageria et al. (2009) reported that sufficient and blended form of fertilizer is absolutely enhance the total nutrient uptake of N. At the same time, productivity of the crop i.e. treatments that accumulates maximum N nutrient gives high yield.
Phosphorus Uptake By Grain And Stover
Application of different blended fertilizer rates on P uptake in grain and stover showed high difference and increasing trends. Due to the blended fertilizer treatment (Table 4), there were highly difference among treatments and the highest P uptake by grain (5.22 Kg / ha) was recorded in treatment treated by NPSZnB and stover (45.53 Kg ha-1) was received in treatment treated by DAP and the lowest (2.27 and 18.38 Kg /ha respectively recorded in control. Application of high blended fertilizer rates enhanced P uptake in grain by 56.5 as compared to the control.
Partial Budget Analysis
The result displayed in Table 5 reveals that, the partial budget analysis of fertilizer rates revealed that the maximum net benefit (79010.2 ETB/ha) was attained from application of 150 kg NPSZnB ha − 1 and the least net benefit (68662.6 ETB/ha) and (69885.9.ETB/ha) was obtained from the application of 50 kg NPSZnB /ha and unfertilized treatment. The dominance analysis showed that all the treatments, except the treatment with NPSZnB fertilizer rate of 100 kg ha − 1, and 150 kg ha − 1 were cost dominated.
The highest marginal rate of return (529%) was obtained from the treatment of 150 kg NPSZnB ha − 1 fertilizer followed by (113%) amended with 100 kg NPSZnB ha − 1 fertilizer (Table 5) gave maximum profit from unit investment. Generally, the analysis of marginal rate of return (MRR) indicated that the application of blended fertilizer on productivity of maize had MRR of greater than 100%. This indicates that maize production is profitable with these all alternatives. According to CIMMYT (1988), application of fertilizer with the marginal rate of return above the minimum level (100%) is economically feasible.
Table 5
Partial and marginal budget analysis of maize response for different NPSZnB fertilizer rates
Treatment | TVC (ETB/ha) | NB (ETB/ha) | DR | MB (ETB/ha) | MC (ETB/ha)) | MRR (%) |
Control | 0 | 69885.9 | - | - | - | |
50 kg ha-1 NPSZnB | 1073 | 68662.6 | D | | | |
100 kg ha-1 NPSZnB | 2133 | 72323.46 | ND | 2437.56 | 2133 | 114 |
150 kg ha-1 NPSZnB | 3396.5 | 79010.2 | ND | 6686.74 | 1263.5 | 529 |
200 kg ha-1 DAP | 4386 | 77332.56 | D | | | |
200 kg/ha NPSZnB | 4452 | 75691.2 | D | | | |
250 kg/ha NPSZnB | 5612 | 76222.3 | D | | | |
Where, TVC = total variable cost, NB = net benefit, MB = Marginal benefit, MC = marginal cost MRR = marginal rate of return, D = dominated, ND = Non dominated, DR = Domination rank |
Based on this result, this suggests that NPSZnB application at the rate of 150 kg ha − 1could be enough for optimum yield and maximum profit in conditions of sufficient nitrogen applied.