**1. Economic importance of maize**

Corn or maize (*Zea mays* L.) is an important cereal crop in the world. It provides staple food to many populations. Maize is the third most important cereal crop in Pakistan after wheat and rice. In Khyber Pakhtunkhwa it ranked second after wheat in its importance [1, 2]. In developing countries, maize is a major source of income to farmers among whom many are poor. Corn is used as animals feed and industrial raw material in the developed countries,

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

while in developing countries mostly used as food for human and feed for animals (http:// cornindia.com/importance-and-utilization-of-maize/). Because of its worldwide distribution and relatively lower price, maize has wider range of uses. For example, it is used directly for human consumption, as livestock and poultry feed, and in nonfood products such as starches, acids, and alcohols. Recently, there has been interest in using maize for production of ethanol as a substitute for petroleum-based fuels. Nutritionally, maize seeds contain 60–68% starch and 7–15% protein. The embryo of corn seeds which forms about 12% of the whole grain is the source of protein, fats, and sugars. Yellow maize is the richest source of vitamin A. Maize contains 1.2–5.7% edible oil. Varieties developed particularly for oil production contain as much as 14%. Maize oil is widely used as a cooking medium and for manufacturing of hydrogenated oil. The oil has the quality of reducing cholesterol in the human blood like sunflower oil. Maize acts as a source in the manufacture of starch, syrup, dextrose, oil, gelatin, lactic acid, etc. Corn flour is used as a thickening agent in the preparation of many edibles like soups, sauces, and custard powder. Corn syrup is used as an agent in confectionary units. Corn sugar (dextrose) is used in pharmaceutical formulations and as a sweetening agent in soft drinks, etc. Corn gel on account of its moisture retention character is used as a bonding agent for ice-cream cones and as a dry Dustin agent for baking products (http://cornindia. com/importance-and-utilization-of-maize/). Integrated nutrient management improves corn growth, leaf area index and light interception, dry matter accumulation and distribution, grain and fodder quality, yield components, grain and biomass yields, harvest index, shelling percentage, and grower's income.

for increasing grain quality (Amanullah and Shah [13]), partial factor productivity (PFP), and agronomic N use efficiency (NUEA) in maize [23]. Amanullah [24] compared the agronomic N use efficiency (NUEA) and harvest index response of different maize genotypes to different N-fertilizer sources (urea, calcium ammonium nitrate (CAN) and ammonium sulfate (AS)) at

Integrated Nutrient Management in Corn Production: Symbiosis for Food Security and Grower's…

relationship with increase in N rate, while harvest index had positive relationship with increase

of AS (AS > CAN > urea). The maize hybrid produced higher NUEA and harvest index than local cultivars (Pioneer-3025 > Jalal > Azam). Khan et al. [15] reported that nitrogen application yielded 41 and 26% more grain than the check (control) in year 1 and year 2, respectively. The hybrid (P-3025) yielded 30 and 24% more grain than the local cultivars in years 1 and 2, respec-

protein contents in corn increased with the application of higher N rates (150 and 200 kg ha−1) as compared with the lower N rates (50 and 100 kg ha−1), while application of ammonium sulphate increased seed oil contents as compared to urea and CAN [25]. Yield components (number of rows ear−1, seeds row−1, seeds ear−1, ears per 100 plants), and both grain and stover yields in corn increased with higher N rate [5]; ammonium sulfate at the highest rate of 200 kg N ha−1 was

Phosphorus is second to nitrogen in total application to crops yet is used by plants in much lower quantities. Unlike N, soil P readily forms weakly soluble mineral compounds in the soil, thus resulting in poor mobility. The major problems under semiarid condition in Northwest Pakistan are (1) low soil moisture and (2) low soil fertility especially P unavailability ([26–28]).

length, grain weight, grain yield, shelling percentage, and net returns [29]. Among the sources of P-fertilizers, diammonium phosphate (DAP) and single super phosphate (SSP) improved growth, dry matter partitioning, and grain yield than Nitrophos (NP) and control [27]. The

leaf area, dry weight of leaf, stem and ear as well as biomass yield, and harvest index [28]. Amanullah et al. [26] also reported that application of DAP and SSP resulted in higher partial

increased maize productivity and profitability [6]. Earlier, Amanullah et al. [28] reported that phosphorus level and its time of application are considered as some of the most important

Asif et al. [18] reported that tasseling, silking, and physiological maturity were delayed when

). Increase in P rate (90 > 60 > 30 > 0 kg P ha−<sup>1</sup>

factors affecting crop growth, dry matter accumulation, and harvest index in maize.

P), and net returns (NR) (Rs. 16,289 and 16,204 ha−<sup>1</sup>

found beneficial in terms of higher productivity & profitability for hybrid maize [5].

). The results revealed that NUEA had negative

, CAN at 100 and 150 kg N ha ha−<sup>1</sup>

http://dx.doi.org/10.5772/intechopen.80995

P), agronomic efficiency (AE) (13.01

P), AE (8.94 kg grains kg−<sup>1</sup>

, while further increase in K level up to 90 kg ha−<sup>1</sup>

), respectively, as

) and tillage depth (45 cm)

P), and

,

5

. Both NUEA and harvest index ranked first with the application

was economical in terms of NR in both years ([15]). Seed

10 days before sowing (DBS) had marked an increase in ear

at 10 DBS increased plant height, number of leaves per plant, mean

various levels (0, 50, 100, 150, and 200 kg ha−<sup>1</sup>

tively. The application of urea at 150 and 200 kg N ha−<sup>1</sup>

factor productivity (PFP) (63.58 and 61.92 kg grains kg−<sup>1</sup>

compared with NP with lower PFP (57.16 kg grains kg−<sup>1</sup>

in N rate up to 150 kg ha−<sup>1</sup>

and AS at 50 and 100 kg N ha ha−<sup>1</sup>

**2.2. Phosphorus management**

Highest level of 90 kg P ha−<sup>1</sup>

highest level of 90 kg P ha−<sup>1</sup>

and 13.71 kg grains kg−<sup>1</sup>

**2.3. Potassium management**

potash levels were increased up to 60 kg ha−<sup>1</sup>

NR (Rs. 4472 ha−<sup>1</sup>
