Research Article

Nutrient Application from Integrated Sources Improve Crop Yield and Soil Properties of Water Eroded Land

Farmanullah Khan*, Samad Khan, Wiqar Ahmad and Imran Khan

Department of Soil and Environmental Sciences, The University of Agriculture, Peshawar, Khyber Pakhtunkhwa, Pakistan.

Received | December 12, 2015; Accepted | July 08, 2016; Published | August 20, 2016

Correspondence | Farmanullah Khan, Department of Soil and Environmental Sciences, The University of Agriculture, Peshawar, Pakistan; Email: [email protected]

Citation | Khan, F., S. Khan, W. Ahmad and I. Khan. 2016. Nutrient application from integrated sources improve crop yield and soil properties of water eroded land. Sarhad Journal of Agriculture, 32(3): 202-211.

DOI | http://dx.doi.org/10.17582/journal.sja/2016.32.3.202.211

Keywords | Crop nutrition, Integrated nutrient sources, Physico-chemical characteristics, Soil fertility, Water eroded land

Introduction

Population increase and changes in dietary habits are important factors affecting food requirements of a nation. In the past few decades, population increase and the resultant increased food requirements compelled Pakistani growers for bringing marginal and sloping lands under cultivation with their inaccurate cultivation techniques (Ali et al., 2007). This practice, no doubt, rewards in the short run but is devastating for precious resources in the long run. The whole fertile surface soil is washed away as runoff after the occurrence of a few rainstorms leading to permanent degradation of soil. Crop productivity on such degraded soil goes uneconomical and restricted with respect to crop choice. Soil losses from a field are dependent upon many factors like type and amount of rainfall, soil characteristics, field slope type and length and soil cover and management factors. Due to these factors, researchers in northern Pakistan have reported soil loss from 2 – 104 t ha-1 year-1 (Ahmad, 1990; Khan and Bhatti, 2000; Khan et al., 2001) with resultant soil physico-chemical deterioration including reduced soil organic matter (SOM) and nutrient concentration, reduced infiltration rate and water holding capacity, and exposure of clayey subsoil. Bhatti et al. (1997) reported loss of 48, 24 and 18 kg ha-1 soil P, N and organic matter, respectively, under water eroded conditions indicating heavy loss of valuable nutrients every year. Bhatti et al. (1998) further reported severe deficiency of available P and K (2.68 and 48 mg kg-1, respectively) under eroded field conditions and the field was also low in organic matter (1.2 to 6.6 g kg-1).

Cultivation of eroded lands need improved management techniques and conservation practices and the incorporation of nutrient from varied sources. Few of these nutrient sources have been counted by Khan et al. (2007) are farmyard manure, compost, humic acid, synthetic fertilizers and their combinations. Under such circumstances, livestock raring is very important way for the provision of farmyard manure required for intensive and sustainable crop husbandry (Reddy et al., 2003). In past, utilization of livestock by-products by the resource poor farming community for household energy purposes created its availability problems for field applications and the crop demand for nutrients is met only with sub optimal rates of NPK fertilizers. This has resulted in a decline in SOM and has negatively affected soil fertility and crop productivity. Chemical fertilizers applied to soils can provide crops with specific nutrient elements, but not with all the essential elements they need. Decreasing SOM is one of the main factors affecting the productivity and the effects are more pronounced in cases of lower NPK fertilizer application.

Imbalanced inorganic fertilization and lack of recycling of nutrients from natural sources adversely effected the fertility and productivity of our soil. Successful restoration of soil fertility require SOM improvement (Banning et al., 2008). Plant nutrient input from a variety of sources has proved to enhance SOM and crop yield on initially poor quality soils (Nawaz et al., 2000; Jadoon et al., 2004). Recently, with the introduction of alternative energy sources (natural gas and LPGs) in many villages of the experimental area, it is the time to inspire the concerned farming community to utilize their livestock bi-products for the restoration of their degraded soils and to obtain a satisfactory level of crop yield and profitable return. This experiment was planned with the objective to determine a reasonable ratio nutrients applied through natural and chemical fertilizers for improvement in yield and soil physico-chemical characteristics of water eroded land.

Methods and Materials

The study was planned in Randomized Complete Block Design (RCBD) at Jagganath village of District Swabi, KPK, Pakistan, during the year 2007-08. Soil was silt loam in texture, non-saline, alkaline (pH 8.1), calcareous (lime 13.75 %) with low SOM (8.04 g kg-1) and poor in P (2.34 mg kg-1) and K (55.25 mg kg-1) availability. Physico-chemical properties of the site are provided in Table 1.

Table 1: Physico-chemical characteristics of soil before sowing

Table 2: Qualitative analysis of farm yard manure applied during the experiment

The treatments consisted of the control, NPK50 (50% of the recommended NPK), NPK75 (75% NPK), NPK100 (100% NPK), FYM10 (10 t ha-1 FYM), NPK50 +FYM10, NPK75+FYM10, NPK100+FYM10, FYM20 (20 t ha-1 FYM), NPK50+FYM20, NPK75+FYM20, NPK100+FYM20. Treatment size was 10 m2 and the experiment was replicated three times. Urea, DAP and Potassium sulphate (SOP) applied as NPK sources. Nitrogen dose was applied in two splits, half during cultivation and half at second irrigation. All P and K were applied during cultivation whilst well decomposed farmyard manure (FYM) of known physico-chemical characteristics (Table 2) was applied one month before sowing. Wheat (Triticum aestivum) variety “Tatara” was sown as a test crop. Besides soil physico-chemical properties, data on grain, biological and straw yield and grain weight were noted in each treatment.

After crop harvest, data on biological yield was recorded by air drying wheat bundles and weighing them separately at interval until a constant dry weight was achieved. Grain yield was recorded by threshing wheat bundles from each plot separately and weighed with top load balance after air drying until a no change in weight was arrived. 200 normal grains from each plot were counted, weighed on top load balance and multiplied by a factor of 5 to convert it to 1000 grain weight.

Soil samples at two depths (0 to 15 and onward to 30 cm) were taken from each plot after crop harvest in the form of undisturbed core samples and disturbed soil samples for further fertility analysis.

In soil physical parameters, bulk density (ρb) = Ms/Vt (Mg m-3) (Blake and Hartge, 1984), Saturation percentage (ωs)= (Mt-Ms)/Ms * 100 (Gardner, 1986) and available water holding capacity (ωa)= (ωfc– ωpwp)/dry weight of the soil sample (g) * 100 (Cassel and Nelson, 1986) were determined through their respective standard procedures where ωfc and ωpwp are water content (g g-1 soil) at 0.3 and 15 bar, respectively. Amongst soil chemical parameters, SOM (Nelson and Sommers, 1982), Mineral N (Mulvaney, 1996), electrical conductivity (Rhodes, 1996) and pH (McClean, 1982), lime content by acid neutralization (Method 23c, USDA HB 60), Plant available phosphorus, potassium, zinc, iron, copper and manganese after AB-DTPA extraction (Soltanpour and Schwab, 1997) were determined by the using their respective standard procedures. Spectrophotometer set at 880 nm was used for phosphorus, flame photometer for potashium and atomic absorption spectrophotometer (Perkin Elmer Model 2380, USA) for micro-nutrients.

Statistical Procedures

Results were subjected to analysis of variance in RCB design using STATISTIX 8.1 software. Significantly different means comparison was carried out by LSD test (Steel and Terrie, 1980). For economic analysis, after considering the cost of fertilizers NPK (Economic Survey of Pakistan 2008-09) and FYM (local market), the incomes from grain yield and straw yield (local market) were used as; Net return = value of increased yield – cost of fertilizers.

Table 3: Effect of single and combined application of chemical fertilizers and FYM on yield parameters

Results (Table 3) revealed significant (p<0.05) increase in yield parameters where the highest 1000 grain weight (GW1000) and maximum grain yield (GY) were obtained with the application of NPK75FYM20. Whilst being statistically at par with NPK100FYM20, NPK75FYM20 showed 26, 20 and 14% higher GW1000 and 99, 76 and 48% higher GY over the control, NPK50 and NPK100, respectively (Table 3). On the other extremity, same treatment (NPK75FYM20) resulted in 20 and 15% more GW1000 and 65 and 23% more GY compared to FYM10 and FYM20, respectively. These results counsel the addition of 20 t ha-1 FYM in conjunction with low NPK by 25% of the recommended dose for highest production. The results further endorsed that integrative use of nutrients from organic and synthetic sources can restitute the fecundity of eroded lands and has asset over their unshared applications. Whilst, Nadeem et al. (2016) termed it the second favourable choice after the recommended inorganic NPK and micronutrients fertilizers in the planner part of Khber Pakhtunkhwa (Dera Ismail Khan) for higher grain yield, highest grain yield (maize) obtained by Jadoon (2004) after the conjunctive cure of FYM and chemical fertilizers in the northern Khyber Pakhtunkhwa supports our results. Such integrated use of nutrient sources have been advocated for improvement in soil OM content (Swarup, 2001), physical characteristics (Hati et al., 2006) and crop productivity (Jadoon, 2004).

Data obtained further showed that chemical fertilizers and FYM, applied singly and united, significantly (P<0.05) augmented the biological yield (BY) and straw yield (SY) over the control (Table 3). The higher BY and SY were obtained with cure of NPK75FYM20 registering an increment of 86, 40 and 30% in BY and 80, 71 and 29% in SY over the control, NPK50 and NPK100, respectively. It was further noted that with regard to BY, FYM10 alone was comparable with NPK50 and FYM20 alone was comparable with NPK100. With regard to SY, NPK75FYM20 was comparable with NPK100FYM20. Yet, all of these nutrient types and combinations were significantly potent compared to the control. Mineral fertilizers alone (NPK50 and NPK100) also showed significant improvement in BY (11 and 43%, respectively) and SY (5 and 39%, respectively) over the control (Table 3). Plant nutrient supplementation through organic manure results in sustaining crop productivity (Patra et al., 2000). Nutrient application from inorganic (NPK) alone and its combination with organic fertilizer significantly improve crop growth rate (Nadeem et. al., 2016). Nutrients from mineral fertilizers get pronto free for the plants uptake to cater for early growth requirements whilst FYM slow decomposition ensure nutrients availability at the latter growth stages. Combination of both sources results in continuous nutrient supply throughout plant life resulting in higher biological yield (Ibrahim et al., 1992; FAO, 1995). Mussgnug et al. (2006) obtained higher yield with FYM application to nutrient deficient soils whilst Sohu et al. (2015) recommended to amend soil for nutrients half from organic and half from inorganic sources. It can be visualized from these results that conjunctive use of FYM and chemical nutrient sources has remodeled eroded soil capacity for crop production. Similar results have been reported by other scientists as well (Nawaz et al., 2000; Jadoon et al., 2004; Bhatti et al., 2005).

Economic Analysis of Fertilizers Application

Economic analysis of crop yield obtained from different fertilizer treatments (Table 4) showed that NPK75FYM20 produced the extremum net economic return (Rs. 43108 ha-1) indicating thrifty significance for profitable wheat yield. Application of inorganic fertilizers (50, 75 and 100% NPK of the recommended dose) excluding any organic fertilizers produced the lowest economic return (Rs.1907, 14208 and 14648, respectively). It can be terminated from these results that the net return per unit area was raised due to the integrated use of organic and artificial nutrient sources and this may provide probably the most viable and sustainable option for cereal based cropping schemes under limiting soil conditions. This further indicated the amelioration of crop productivity of eroded lands making it more profitable and sustainable if practiced over time.

Table 4: Economic analysis of fertilizers (Pak Rs.)

Table 5: Effect of inorganic fertilizer alone and in combination with FYM on soil physico-chemical properties

Looking at overall changes in soil physico-chemical characteristics (Table 5), the physical properties like bulk density (ρb), available water (ωa) and saturation water (ωs) were affected by combined use of nutrient sources (FYM and commercial fertilizers). The lowest values of ρb (1.08 and 1.21 Mg m-3) were noted with NPK100FYM20 (Table 5) followed by NPK75FYM20 (1.14 and 1.25 Mg m-3) in plough layer (0-15 cm) and deep (15-30 cm), respectively. Soil ρb in FYM10 (1.29 Mg m-3) FYM20 (1.17 Mg m-3) reduced significantly from its peak level in the control (1.4 Mg m-3). This showed that FYM20 was more effective in decreasing ρb. Available water (ωa) and saturation water (ωs) were maximum (23.37 and 50.13%, respectively) in the soil treated with NPK100FYM20 followed by NPK75FYM20 (23.16 and 48.73%, respectively) in 0-15 cm soil (Table 3). Compared to the control (17.27 and 35.37%, respectively), ωa and ωs with FYM10 were 19.68 and 41.32%, while with FYM20, it were 22.67 and 46.65%, respectively. Similar trends in ωa and ωs were also observed at 15-30 cm soil depth. Increased SOM after FYM input and higher biomass production might be responsible for higher ωa and ωs. Sohu et al. (2015) recommended half of the required inorganic fertilizer in combination with organic sources of nutrients for improved organic matter stock and soil fertility status whilst Hati et al. (2006) and Ahmad et al. (2014) reported improved soil physical characteristics after application of similar soil amendments. Farmyard manure, on its decomposition, might have released Ca2+ helping flocculation of soil particles and resulting in increased total porosity (Sanchez et al., 1989) and subsequent increase in ωs and ωa whilst decreasing the ρb (Haynes and Naidu, 1998). Previous work also shows correlation between ρb and ωs and ωa to be significantly negative (Ahmad et al., 2014). Role of FYM in conservation of soil moisture has been reported by many researchers (Jadoon et al., 2004; Hati et al., 2006).

The lowest pH value (8.01) was noted in the soil treated with NPK100FYM20 followed by FYM20 and FYM10 alone (Table 5). This drop down in pH might be the result of H+ produced during the degradation and nitrification of FYM and commercial fertilizers (Akram et al., 2007). Soil depth of 15-30 cm also showed similar results with regard to soil pH..There was no significant change in EC1:5, which, however, was higher deep into the soil (15-30 cm) compared to the plough layer (0-15 cm).

Soil Organic matter (OM) content increased significantly (P<0.05) after the application of conjunctive nutrient sources. Highest OM content (13.83 g kg-1) was observed in NPK100FYM20 followed by NPK75FYM20 (12.83 g kg-1). Compared to the control (6.30 g kg-1), OM content with the application of FYM10 and FYM20 was 9.0 g kg-1 and 12.23 g kg-1 respectively. The same trend of augmented OM was also found at the 15-30 cm depth. Wang et al. (2000) concluded that application of organic materials increased OM by 1.17 to 2.85 g kg-1 soil and reduced the oxidation stability of soil OM. The increased OM might be due to increased root mass and added FYM. Rasool et al. (2007) obtained 44% more OM, 2.5 fold higher total C and 5 fold higher labile C in manured (35 t FYM ha-1 yr-1) plots. Eventually, proper manuring become an essential practice for optimum soil health and sustained crop production (Chaudhri et. al., 1998).

Table 6: Effect of sole inorganic fertilizer and in combination with FYM on plant available nutrients concentration in soil

Mineral N and plant available P and K were increased to adequate levels in NPK100FYM20 followed by NPK75FYM20 (Table 6). The increase in Cu, Zn, Fe and Mn was non-significant. Iqrar and Tariq (2002) also reported that AB-DTPA extractable Zn and Cu were not affected with organic material application in short term experiments. However, despite their low nutrient concentration (Zaman et. al., 2004), organic manure possesses the potential to improve soil health and quality if used correctly for long time (Ahmad et. al., 2013). Initial levels of N, P and K were deficient and their levels increased due to the cumulative effect of commercial fertilizers and FYM. It was evident from the data (Table 6) that in the plough layer, sole inorganic and combined with FYM significantly (P<0.05) increased the post-harvest soil mineral N. Maximum post-harvest soil N of was observed in NPK100FYM20 (23.41 mg kg-1) treatment followed by NPK75FYM20 (22.27 mg kg-1). Soil mineral N with FYM10 was 12.16 mg kg-1, while with FYM20 it was 20.23 mg kg-1 while with control it was 8.21 mg kg-1. The maximum post-harvest soil mineral N concentration of 22.92 mg kg-1 was recorded in NPK100FYM20 followed by 22.23 mg kg-1 in NPK75FYM20 (Table 6) in the second depth (15-30cm).

The highest plant available P and K (7.61 and 121.32 mg kg-1, respectively) were recorded in NPK100FYM20 followed by NPK75FYM20 (6.53 and 85.01 mg kg-1). Plant available P and K contents after the addition of FYM10 were 3.53 mg kg-1 P and 67.80 mg kg-1 K, while with FYM20, the extractable P and K contents were 4.48 and 71.46 mg kg-1, respectively, compared to soil native values in control (1.81 mg kg-1 P and 56.17 mg kg -1 K),. Similarly, with depth (15-30 cm) the maximum post-harvest available P and K contents of 6.66 and 107.99 mg kg-1, were recorded in NPK100FYM20 followed by 6.07 mg kg-1 P and 85.01 mg kg-1 K in NPK75FYM20 (Table 6). Nutrient loss from top soil with sheet and rill erosion (Bhatti et. al., 1997) and the agricultural activities with elevated nutrient exhaustion from soil plant system and the attendant small and imbalanced fertilization resulted in deteriorating soil fertility status (Sohu et. al., 2015). Use of fertilizers from both organic and inorganic origin not only elevate the nutrient status of soil (Pratt, 2008) but also bring about variation in physical, chemical and biological soil characteristics (Motavalli et al., 2003). Rasheed et al. (2003) and Ahmad and Khan (2014) also reported that use of organic fertilizer in conjunction with inorganic NPK increased plant available nutrient content in soil. There was also another possible effect of FYM through releasing organic acids after microbial decomposition (Ayaga et al., 2006) which could have solubilized soil P (Ahmad, 1999) and chelated Zn (Bhatti et al., 1982; Barak and Helmke, 1993).

Conclusions

This study concluded that integrated use of 75% NPK+20 t FYM ha-1 produced better and economical yield of wheat grown under rain-fed conditions along with improved physical condition of the soil and its fertility status. If practiced in long term, it will reclaim degraded soil conditions through ameliorating its physical and chemical characteristics and thus will have favourable impact on the environment.

Authors’ Contribution

Prof. Dr. Farmnaullah Khan designed and managed the conduction of the experiment, Mr. Samad Khan was involved in field installation of the experiment, agronomic management and data collection, Dr. Wiqar Ahmad contributed in statistical analysis and manuscript writing and Mr. Imran Khan helped in data entry, storage and tabling and review collection.

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