A field experiment was conducted to evaluate the effect of different tillage practices and sowing methods on the morphological and physiological attributes of maize (Zea mays L.) during spring, 2012 at Agronomic Research Area, University of Agriculture Faisalabad Pakistan. Pre-sowing soil samples were collected from experimental area with the help of a soil auger to a depth of 0 - 30 cm and then air dried for physico-chemical analysis. The soil was found to be normal but low in organic matter. Further characteristics of experimental soil are given in the Table 1. Maize hybrid “Pioneer-32T16” was sown, with 30 kg·ha⁻¹ seed rate, in well prepared seed bed according to the treatments on 24^th February, 2012. The experiment was laid out in randomized complete block design (RCBD) with split plot arrangement and repeated thrice. Experiment comprised of Tillage Practices (Main-Plots) i.e., T₁: Conventional tillage (Disc harrow twice + cultivator once + planking); T₂: Minimum tillage (Cultivator twice + planking) and T₃: Deep tillage (Chisel plough twice + cultivator once + planking) as well as sowing methods (Sub-Plots) i.e., S₁: Flat sowing (R × R = 60 cm); S₂: Ridge sowing (R × R = 60 cm) and S₃: Bed sowing (Bed = 120 cm). Tractor, Planker, Hand Drill, Spade and Chisel Plough were used for tillage and sowing purpose. Fertilizer was applied @ 250:125:125 kg NPK·ha⁻¹. Whole quantity of Phosphorus and Potash was applied prior to seeding as a basal dose while nitrogen was applied in three splits (1/3^rd at the time of sowing, 1/3^rd at five leaf stage and 1/3^rd at tasseling stage. Leaf area index (LAI) and crop growth rate (CGR) were computed by the formulae given by [11] [12] , respectively.

where

W₁ = Total dry matter at the first harvest

W₂ = Total dry matter at the second harvest

t₁ = Date of observation of first dry matter

t₂ = Date of observation of second dry matter

All other agronomic practices was done by using standard procedures and at the end crop was harvested and cobs were removed from husk and were kept for sun drying to minimize moisture content of grain and easy shelling. After certain period of sun drying, the cobs were shelled with the help of maize sheller to separate grains from pith. The data was collected analyzed by using Fisher analysis of variance technique and significant treatment means were compared by the least significant difference (LSD) test at 0.05 probability level [13] where as economic analysis was carried out to look into comparative benefits of different treatment combinations [14] .

Data regarding germination count·m⁻² as affected by various tillage practices and sowing methods are depicted in Table 2. It is obvious from the table that there were non-significant differences in germination count·m⁻² when maize hybrid was sown under different tillage practices. Maximum germination count of 7.1 plants·m⁻² was observed in deep and minimum tillage while minimum (6.7 m⁻²) was recorded in conventional tillage but they were not varying up to the level of significance. As regard the maize sowing methods, there were significant differences in germination count·m⁻². Maximum germination count (7.8 m⁻²) was observed in ridge sowing that was at par with bed sowing while flat sowing attained minimum germination count of 6.1 plants·m⁻². Greater germination·m⁻² in ridge sowing might be due optimum moisture level and nutrients availability.

Plant height at maturity was affected appreciably by different tillage practices and sowing methods. The plant height was found maximum (213.04 cm) in deep tillage and lowest (201.84 cm) in minimum tillage that was found statistically similar with conventional tillage (204.00 cm). As far sowing methods are concerned, ridge sown maize produced maximum plant height of 211.86 cm that was statistically comparable with bed sowing (210.40 cm) while minimum plant height of 196.62 cm was recorded in flat sowing. Moreover, interaction between tillage practices and sowing methods was found non-significant.

Various tillage systems and sowing methods are depicted in Table 2 clarified that neither the individual factors nor the interaction affect stem diameters of maize hybrid noticeably, when it was sown with different sowing methods under different tillage practices. The stem diameter ranged from 11.30 mm to 13.30 mm but the differences were found statistically non-significant.

Data regarding the effect of different tillage practices and sowing methods on leaf area per plant 70 (days after

Any two means not sharing a letter in common in the same column differ significantly at p ≤ 0.05.

sowing) DAS of maize hybrid are shown in Figure 1. The leaf area was recorded at 40, 55, 70 and 85 cm⁻² days after sowing. It further elucidated that leaf area per plant varied significantly when maize hybrid was sown with different sowing methods under various tillage systems. Leaf area per plant was highest in the plots where ridge sowing was practiced under deep tillage while lowest was recorded in the flat sowing under minimum tillage.

Figure 2 expounded that leaf area index (LAI) varied extensively when maize hybrid was sown with different sowing methods under various tillage systems. Maximum LAI was recorded at 40, 55 and 70 DAS in the plots where ridge sowing was done under deep tillage while minimum in the flat sown maize where minimum tillage was practiced. In the middle phase of growth, leaf area index was continued to increase while decreased towards maturity. The results were much better in conventional tillage with ridge and bed sowing. Moreover, all sowing methods except flat sowing were found effective regarding improvement of LAI.

Various tillage practices and sowing methods affected the crop growth rate (CGR) of maize hybrid under study (Figure 3). The CGR was calculated within the certain periods (40 - 55, 55 - 70 and 70 - 85 DAS) and was measured highest at all stages in the plots where ridge sowing and bed sowing was done under deep tillage while

lowest was recorded in the flat sowing where minimum tillage was practiced. CGR continued to increase up to middle phase of growth then declined towards maturity. All sowing methods except flat sowing increased the crop growth rate. The results were much better in conventional tillage with ridge and bed sowing.

Table 2 illustrated that number of leaves per plant was affected radically by different tillage practices. The number of leaves per plant was higher (11.89) in the deep tillage that was at par with the conventional tillage (11.60) while lower number of leaves per plant (11.36) was found in minimum tillage that was closely followed by conventional tillage. As for sowing methods were concerned, maximum number of leaves per plant was produced in bed sown maize (11.82) while the minimum number of leaves was produced in ridge sowing (11.49) but these were not varying up to the level of significance. Furthermore, a significant interactive effect was also noted between various tillage practices and sowing methods for number of leaves per plant. All the sowing methods including flat, ridge and bed sowing showed statistically non-significant differences in the means regarding number of leaves per plant under conventional and minimum tillage. But under deep tillage, maize on ridges produced maximum number of leaves per plant (12.07) that was statistically similar with bed sown maize (12.33) while flat sown maize produced significantly minimum number of leaves per plant (12.27).

Data regarding days to 50% tasseling indicated that there were non-significant differences in days to 50% tasseling when maize hybrid was sown under different tillage practices. Maximum days to 50% tasseling (71.55 days) were observed from minimum tillage while minimum days to 50% tasseling (70.22 days) were recorded in deep tillage but did not differ significantly. As regard the sowing methods, there a significant difference in days to 50% tasseling was observed. Maximum days to 50% tasseling (72.44 days) were recorded in flat sowing while minimum days were recorded in bed sown maize (69.89 days) that was similar with ridge sown maize (70.44 days).

A non-significant difference in days to 50% silking was observed when maize hybrid was sown under different tillage practices (Table 2). Maximum days to 50% silking (72.44 days) were observed minimum tillage and conventional tillage while minimum days to 50% silking (71.44 days) were recorded in deep tillage but they were not varying up to the level of significance whereas sowing methods significantly affected to days to 50% silking. Maximum days to 50% silking (73.77 days) were observed in flat sowing while minimum days (71.11) were recorded in bed sown maize that was similar with ridge sown maize (71.44 days).

It is clear from the Table 3 that highest net return of Rs. 85162 was recorded in the treatment where ridge sowing of maize hybrid was done under deep tillage while lowest net return of Rs. 56984 was recorded in flat sown maize under minimum tillage. As farmers are more interested in variability in benefits than yields, therefore net field benefits (NFB) were calculated against the variable cost. Table 3 further revealed that maximum NFB of Rs. 173788 was achieved in the treatment where ridge sowing of maize hybrid was done under deep tillage. The minimum NFB of Rs. 145610 was obtained where flat sowing was done under conventional tillage. Moreover, the efficiency of tillage practices and sowing methods on maize was determined from the benefit cost ratio. The maximum benefit cost ratio (BCR) of 1.70 was found where ridge sowing of maize was practiced under deep tillage.