**5. Maize response to biofertilizers (beneficial microbes)**

Biofertilizers (beneficial microbes) are known to play many vital roles in soil fertility, crop productivity, and profitability. Beneficial microbes reduce the use of chemical fertilizers and thereby reduce environmental pollution caused by chemical fertilizers. Beneficial microbes reduce cost of production and so increase grower's income and profitability [40]. Our recent publications [1, 10, 16] indicated significant (P ≤ 0.05) differences in growth, yield components, yield, and harvest index between the seeds treated with PSB (+) and without PSB (−). Amanullah and Khan [16] conducted field trial to study the effects of P levels, compost application times, and seed inoculation with phosphate-solubilizing bacteria (PSB) on the yield and yield components of maize (*Zea mays* L., cv. Azam). Maize seed inoculated with PSB (+) had tremendously increased yield and yield components of maize over PSB-control plots (−). Amanullah and Khalid [10] conducted field experiment to investigate impact of P levels (40, 80, 120, and 160 kg P ha−<sup>1</sup> ) and animal manures (poultry, cattle, and sheep manures) with (+) and without (−) phosphate-solubilizing bacteria (PSB) on phenological development, growth, and biomass yield of hybrid maize "CS-200." The plots with PSB (+) produced significantly taller plants with higher mean single leaf area and leaf area index and produced the highest biomass yield. Amanullah and Khalid [1] conducted a field trial to investigate the impact of the integrated use of different animal manures and phosphorus levels on yield and yield components of hybrid maize (CS-200) with (+) and without (−) phosphate-solubilizing bacteria (PSB). Maize seeds treated with PSB (+) before sowing had produced higher yield and yield components than untreated seeds (−). We concluded from this study that combined application of 160 kg P ha−<sup>1</sup> + poultry manure + seed treatment with PSB (+) could improve corn productivity and profitability under semiarid condition.

#### **6. Maize response to integrated nutrient management**

The basic concept underlying integrated nutrient management (INM) is the maintenance and possible improvement in soil health for sustained crop productivity and sustainability. Amanullah et al. [7] reported that application of 120 kg N ha−<sup>1</sup> + 2 t compost ha−<sup>1</sup> under deep tillage system (45 cm) could improve spring maize yield and yield-contributing traits. Amanullah et al. [9] reported that application of the highest level of sulfur at 40 kg S ha−<sup>1</sup> + N level at 160 kg N ha−<sup>1</sup> increased maize productivity. Amanullah and Khan [16] reported that compost applied at sowing time + P applied at the two higher rates (75 and 100 kg P ha−<sup>1</sup> ) + PSB (phosphate-solubilizing bacteria) tremendously increased yield and yield components of maize. Application of 120 kg P ha−<sup>1</sup> + poultry manure along with seed treatment with PSB improved growth and total biomass [10] and increased yield and yield components of maize [1]. According to Iqbal et al. [14], application of K at the highest rate of 90 kg ha−<sup>1</sup> in two equal splits (50% at sowing +50% at V9 stage) along with cattle dung (5 t ha−<sup>1</sup> ) could improve number and area of leaves, dry matter partitioning, biomass yield, and harvest index under limited irrigation condition. Amanullah [41] reported that integrated use of organic carbon sources, plant nutrients and bio-fertilizers is key to improve field crops productivity under arid and semiarid climates.
