Growth parameters
Results from experiment showed that among nutrient management treatments, 100%NPK+PM@ 10t/ha (204.00 cm), PM @10t/ha (199.30 cm) and 100%NPK+PM @5t/ha (193.68 cm) gave the taller maize plants followed by 100%NPK (186.90 cm) and PM @5t/ha (185.60 cm) while the smallest plant (156.67 cm) was recorded in control (Table 1). Control plots recorded shortest maize plants due to limited nutrients supply in these plots. Superior plant height was recognized due to gradual release of essential plant nutrients in a combination of NPK and poultry manure as required by the plant.
Among nutrient management treatments, 100% NPK+ PM@10t/ha, PM @10t/ha and 100% NPK+PM @5t/ha recorded higher number of leaves per plant (12.87, 12.80, 12.45 per plant) followed by 100% NPK (12.13 per plant) and PM @5t/ha (11.07 per plant) while the minimum (9.97 per plant) was described in control. Leaves in each plant was inhibited due to restricted nutrients supply in the control plots. Similar trends were recorded in leaf length of the maize plant where by T3 recorded highest leaf length (89.93 cm) and control recorded the lowest (69.80 cm) (Table 1).
Analysis of variance showed significant differences for leaf width (cm), stem girth (cm) and leaf area (cm
2) amongst various inorganic and organic nutrient sole and combined application combinations. The significantly different treatments indicate positive responses of various treatments used on these growth parameters. Among sole and combined nutrient management treatments 100%NPK+PM @10t/ha recorded highest leaf width, stem girth and leaf area (9.3 cm,7.5 cm,839.80 cm
2) which was followed by PM @10t/ha, 100%NPK+PM @5t/ha, PM @5t/ha, 100% NPK and while the minimum leaf width, stem girth and leaf area (7.10 cm, 4.53 cm, 496.70 cm
2) was recorded in control plots. Stem girth and leaf area were inhibited due to restricted nutrients supply in the control plots (Table 1).
Production potential of maize
Combined application of organic and inorganic sources of fertilization had a significant result of maize grain yield. Maximum grain yield of 2511 kg/ha obtained from 100% NPK+PM @10t/ha followed by 100%NPK+PM @5t/ha and 100% NPK (2267 kg/ha and 2185 kg/ha, respectively). Minimum grain yield of 1033 kg/ha obtained in control.
Results obtained are in agreement with those of
Fanuel and Gifole (2013);
Afe et al., (2015) and
Magda et al., (2015). They found that higher grain yield might be due to better growth, development and dry matter buildup by proper supply of nutrients in plant and increased availability of other plant nutrients with the corresponding nitrogen application source. Treatment 100%NPK+PM @10t/ha gave the highest values of growth components (Table 1) which were consequently reflected on grain yield.
Under the influence of sole and combined application of organic and inorganic sources of fertilization, maize stover yield varied significantly. Maximum stover yield of 4776 kg/ha was recorded by 100%NPK+PM @10t/ha followed by 100% NPK+PM @5t/ha and 100% NPK, 4310 and 4149 kg/ha, respectively. Minimum stover yield of 1966 kg/ha was obtained in control.
Biological yield was significantly affected by the investigated sole and combined treatments (Table 2). The highest biological yield of 7287 kg/ha was recorded in 100%NPK+PM @10t/ha, while, minimum was produced by Control.
Dilshad et al., (2010) and
Khan et al., (2016) found that combined use of organic and inorganic nutrients sources produced highest maize biological yield.
Production efficiency
Treatment 100%NPK+PM @10t/ha recorded maximum production efficiency (20.93 kg/day/ha) which was significantly higher among all other treatments. Minimum production efficiency of 13.53 kg/day/ha was recorded in treatment control (Table 2). This might be because of increase in grain yield under 100%NPK+PM @10t/ha which also enhanced production efficiency per day. Combination of inorganic fertilizer with organic manure enhance the efficacy of inorganic fertilizers. Superior plant growth might have aided in synthesis of larger quantity of food material which was later translocated into developing cobs with increasing cob length and diameter.
Treatment 100% NPK+PM @10t/ha recorded significantly superior (2511 kg/ha) grain yield than inorganic fertilizers or organic manure alone tested for growth and yield of maize. This was followed by 100%NPK+PM @5 t/ha, 100% NPK, PM @10t/ha, PM @5t/ha and control.