Effects of Organic and Inorganic Fertilization: Response of Wheat Cultivation and Interaction with Soil Properties

The term fertilization is generally used to describe the sum of management practices to maintain or improve the productivity of soils and crops. This latter is also known to affect plant growth, productivity, crop quality and influences soil quality. Recently, chemical fertilizers have been progressively replacing traditional organic manure aiming to ameliorate crop yields. However, the risk of soil pollution and the degradation of its productivity due to the utilization of these chemicals is considerable (Hati et al., 2008); Naveed et al. (2013); Blanco-Canqui et al. (2014); Bi et al. (2015).

Thus, maintaining soil productivity is a challenging issue particularly in extensive agriculture adopted in developing countries (Rezig et al., 2012).

Therefore, these soils can be recovered by supplementing commercial fertilizers with organic wastes, such as household garbage compost and farmyard manure (Wong and Wong 1989; Raymond and Roy 1992; Chu and Bradshaw 1996; Agele 2000), as soil fertilizers can improve  the recycling of nutrients by supporting the cropping system (El-Shakweer  et al., 1998). It also ameliorates soil fertility through the activation of its microbial biomass.

At the same time, using intermediate crops as green manure may be beneficial to the sustainability of the cropping system and soil fertility as it participates in the enrichment of organic matter in the soil by providing plant residues reducing erosion by soil cover and retaining nutrients by biological fixation (Sørensen, 1991; Merbach et al., 1997; Dinnes et al., 2002; Nziguheba and B¨unemann, 2005). Therefore, PGPR (Plant Growth Promoting Rhizobacteria) can be used for biological fertilization of the soil given its importance in enriching the soil by biological nitrogen fixation (Benmati et al., 2020).

Wheat (Triticum aestivum L.) is one of the most widely grown cereal crops, contributing to the global food supply and economic security (Vichitra et al., 2017). The contribution of fertilizers can contribute to the improvement of wheat yields; however, the rational use of fertilizers must be based on knowledge of the initial richness of the soil in fertilizing elements and their availability in periods of high use by crops and the desired performance objective. Nutrient management is an important issue in autumn rice and wheat a precise schedule should be followed to get optimum result (Debasish and Saikia, 2018). In addition, the role of soil is fundamental in primary production as it provides chlorophyll plants with the mineral ions they need, so the soil must be managed sustainably as it does not regenerate quickly.

The impoverishment of soils by the intensification of crops and the excessive use of fertilizers is today a major problem in ecology, because it can lead to the depletion and destruction of this resource. The use of manure and / or green manure seems to be the most attractive method, especially since it is respectful of the environment and the sustainability of the soil.

In Constantine, cereal producers complain about the concern for yield despite sufficient rainfall and the application of adequate cultivation methods.

According to the protocols of the national durum wheat network in Algeria, it appears that soils are starting to lose their viability due to the overuse of chemical fertilizers, which are sometimes unapproved. To cope with these constraints, great attention must be focused on the change in soil quality after heavy application of chemical fertilizers.

To this end, we have found useful to try in this work, to identify the behavior of the soil and the yield of the durum wheat plant towards chemical and / or organic fertilizers.

This research was carried out in a real environment during the 2017-2018 cropping season in Algeria in the municipality of El khroub, Wilaya of Constantine Algeria in the open field (Fig 1) on three farms whose geographic coordinates are as follows: Plot(S1) : 36°11'56, 96''N et 6°41'4''E, Plot(S2): 36°12'06,00N 6°36'57,80''E and Plot(S3): 36°14'41, 24184 N 6°37'25,09968''E (Fig 1).



Two types of fertilizers used during the test; ternary mineral fertilizer NPK (15-15-15) and organic fertilizer; cattle manure (cultivation of wheat annually) and mineral fertilizer in plot (S02) and plot (S03) previous type of culture leguminous crops and flanking soil respectively (Table 1). In each of the experimental plots, sixty soil samples are collected using an auger before (initial) treatment and after harvesting every 10 m diagonally at 0-25 cm depth over an area of one hectare.



The soil samples are dried and sieved at 2mm to determine the following parameters: the pH according to a ratio 1 / 2.5 (NF X 31-103,1998), the electrical conductivity CE according to a ratio of 1/5 (ISO11265, 1994), the total limestone using the Bernard calcimeter according to standard NFISO10693 (1995), the organic matter is carried out according to the method of Walkley and Black (Duchaufour, 1991), the nitrogen is determined by the Kjeldahl method according to ISO11261 (1995) and  phosphorus by the Olsen method and yield estimation.
 
Data analysis
 
Analysis of variance (ANOVA) and separation of means (Newman-Keuls test) are used to determine differences between treatments, using IBM SPSS Statistics ver. 23.0. The changes in soil characteristics before and after treatments are calculated using the formula:
 

X%= 100*(X2-X1)/X1

Where,
X1= Value of the parameter considered before processing.
X2= Value of the parameter considered after processing.

In our experience, the pH as well as the EC of the soil receiving organic amendments have increased compared to other treatments, values range from 8.14 to 8.39 for the pH and from 189.22 µs /cm to 281.46 µs /cm for the EC (Table 2).



We recorded a decrease in the pH and EC from 8.36 to 8.31 and from 525.31 µs /cm to 274.48 µs /cm respectively (Table 2). In their studies in rice-wheat system Dhaliwal et al., (2012) report similar results by studying the impact of the combined use of organic and inorganic fertilization on soil properties. Interestingly, Babu et al., (2007) report a slight decrease in soil pH and an increase in EC due to the application of organic fertilizers while Jagtap et al., (2007) discussed the influence of integrated nutrient management on soil properties, that adding FYM with chemical fertilizers reduces soil pH and increases electrical conductivity.

Whereas for total limestone (CT), there is no change in soil treated with bovine manure and an increase in mineral fertilizer-treated soil of 23.26% and 95.49% for treated soil treated with mineral fertilizer and precede legume.

After treatment, we observed a marked increase in MO of the soil treated with bovine manure (4.45%) (Fig 2), as well as the one under mineral fertilizer with a legume rotation (3.67%). Analysis of the variance reveals a significant treatment effect (p<0.05). 

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Our results are consistent with those of Celik et al., (2010) who demonstrated the long-term effects of organic and mineral fertilizers on the chemical properties of semi-arid Mediterranean soils. They reported that the MO content is interestingly higher with manure application while mineral fertilizers has no effect on MO accumulation.

In our experiment Organic soil, C is higher in treatments receiving organic (cattle smoke) and organic fertilizers with crop rotation (intermediate legume) compared to soils receiving only inorganic fertilizers. Increase is 71.62%, 64.84%, 21.49% respectively this increase is highlighted by the analysis of variance which reveals a significant treatment effect (p<0.05%).

The highest nitrogen and phosphorus content is recorded in soil receiving bovine manure (Table 1) Many studies (Sarma et al., 2015); Hemalatha and Chellamuthu (2013); Singh et al., (2006a) reported that manure application results in an increase of N and P amounts in soil.

The increase in N content available with the addition of organic fertilizers may be due to the release of nitrogen through the decomposition of organic fertilizers (Narwal and Antil 2005). But after harvest, there is a 10.17% decrease in the soil receiving bovine manure, while for soil treated with mineral fertilizer alone there is an increase of 3.51% and 31.37% for soil treated with mineral fertilizer with legume rotation preceding results According to the results obtained by Shahid et al., (2015).

The levels of N, P and K available in the soil are significantly affected by different fertilization treatments (Table 2). It has been demonstrated that long-term manure application and chemical fertilizers led to significant increase values of N available in the soil compared to other fertilization treatments. Dhaliwal Walia (2008) found that the application of fertilizer and manure results in a significant improvement the accumulation of available N levels of underground soil. This is consistent with our work, which shows an increase in N only in soil that has received organic mineralization and that of an intermediate chemical culture (NPK) with a legume rotation. We can conclude that the application of organic fertilizers increases the nitrogen available in the soil.

Furthermore, Singh and Singh (2013) also reported that the P available in the soil is improved through the combined use of fertilizer and manure compared to 100% NPK. Several groups have developed models for applying the main and micronutrients with all soil amendments for large areas, taking into account livestock manure, bio solids, phosphate and other fertilizers.

At the same time there was an increase in k concentration for the three treatments of 13.33%, 18.75% and 37.50% and a marked decrease for phosphorus of around 27.67%,3 1.22% and 49.79% respectively (Fig 2).

The high amounts of K in treatment can be due to bovine manure supplement with K applied to the soil each year, which could provide a certain amount of K and may insure the interaction of organic matter with clay. The decomposition of organic matter releases a substantial amount of CO2 that forms carbonic acid after its dissolution in water and is responsible for the decomposition of certain primary minerals leading to the release of nutrients (Rajneesh et al., 2017). 

A similar effect of the addition of manure is demonstrated by Hemalatha and Chellamuthu (2013); Mazumdar et al., (2014); Sathish et al., (2011). Singh et al., (2006b) observed that the level of SOC, total N and available P increases significantly due to the application of manure alone or in combination with chemical fertilizers. The study by Singh, et al., (2008) demonstrated  that appliying FYM, VC, green manure and rice residue in the soil alone or in combination with bio fertilizers added to NPK, improved soil fertility and maintained high levels of productivity.

Accordingly, Kumar and Prasad’s (2008) studies showed a significant increase of available N, P and K levels in soils due to the addition of green manure and green gram residues and their incorporation into the rice wheat growing system.

The best result of yield is obtained in the plot treated with bovine manure and the plot treated with chemical fertilizer with an intermediate crop that is in the order of 46 q/ha and 35 q/ha (Table 3) compared to the treatment with the mineral fertilizer alone; this could be due to an ameliorated availability of soil nutrients (Marschner 2011).



Our findings are in concordance with those of Shirani et al., (2002) and Iqbal et al., (2005) who reported that application in manure alone or in combination with different tillage practices improves plant growth and yields.

The results of different treatment’s show that; cattle manure has promoted the availability of nutrients and especially organic matter Organic manure has achieved the best yield, when mineral fertilization has recorded the lowest yield. However, the use of manure and/or green manure seems to be the most attractive method, especially as it is environmentally friendly.

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