Integrated effect of organic waste and NPK fertilizers on nutrients uptake in potato crop and soil fertility

The present research was carried out at Nuclear Institute of Food and Agriculture (NIFA), Peshawar Pakistan, to evaluate the integrated response of organic waste and N-P-K fertilizers to nutrients concentration in potato tuber and soil fertility. Fifteen treatment combinations with three replications were used in RCB design. Potato tubers and soil samples (0-15 and 15-30 cm depth) was collected before and after the experiment were analyzed. Data indicated that combined use of organic waste and N-P-K fertilizers significantly improved soil fertility and nutrients concentration in potato tuber. Higher nitrogen (N) (2.10g 100g), phosphorus (P) (0.30g 100g) and potassium (K) (3.16g 100g) concentration were recorded with treatments (municipal solid waste (MSW)+ half NPK) and (Filter cake +full NPK) as compared to control. Maximum total soil N, AB-DTPA extractable P, K and micronutrients were recorded with (MSW+ half NPK) and (Filter cake +full NPK) at both depths. Investigation revealed that the combined use of organic waste and chemical fertilizers beneficial to soil and plant. Moreover, treatments (MSW +full NPK) and (Filter cake + full NPK) seemed to be an adequate dose, for sustainable nutrients concentration in potato tuber and soil fertility.


Introduction
Pakistan is an agriculture country and most of the people are related to agriculture sector.According to an estimate, less than 1% organic matter is present and 100% of soil is deficient of some nutrients.Application of organic manure not only improving soil fertility but also enhance crop productivity when available to crop at approprate level [1].Organic matter play a multi role in soil, such as increasing of organic matter and to release the nutrients throughout in growing plant; also increase the mobility of moisture, interm of water holding capacity (AWHC) and buffering capacity of soil [2].Crops residue, municipal waste enhance physico-chemical properties and fertility status of soil, resulting better productivity [3].Composts are also indispensible to maximize organic matter in those area where organic matter contents are very low.The main causes of low production in Pakistan are nutrients deficiencies, improper use of chemical fertilizers, low organic matter and poor physical condition of soil [4].Balance use of synthetic fertilizers are essential to get economical produce, while imbalance and improper time application, significantly loss most of essential nutrients from the soil through leaching and volatilization [5].
Potato is an important crop of world, including Pakistan, ranked on 4 th in the world and 7 th in Pakistan.It is mostly cultivated in hilly area of North West Khyber Pakhtunkhwa and plain of Punjab.Potato crop can be cultivated in a year three times such as spring and in the plain area it is grown in autumn while in the hilly area in summer.In Pakistan it is cultivated on area of 0.14 million hectares, with total production of 2.55 million tons, while in Khyber Pakhtunkhwa (KPK) it is cultivated on 9.20 thousand hectares and with total production is 0.12 million tons.In Pakistan average yield per hectare is 22.7 tons, while in KPK the average yield per hectare is 13.  1.

Field procedure and treatment
The experiment consisted of fifteen treatments combination, using appropriate RCB design, replicated thrice.Ridges was made and potato were sown on 30 cm high and ridges distance was kept 80 cm.Different treatments combinations including control, farm yard manure, municipal solid waste, NPK full, tomato residue + half NPK, filter cake + half NPK, tomato residue + full NPK, filter cake + full NPK, recommended PK, tomato residue alone, filter cake alone, (farm yard manure) FYM + half NPK, MSW + half NPK, FYM + full NPK and MSW + full NPK.All P and K were applied at the time of sowing while N was applied in split, half at sowing and half at the time of earthing off.

Statistical analysis
Means were separated using Duncan's Multiple Range Tests at 0.05 level of probability as Fratio was significant.

Results and discussions Organic matter and NPK concentration in soil
Data showed that treatment combinations significantly (P ≤ 0.05) affect the total N, AB-DTPA extractable P and K as compared to control (Table 2).At depth of 0-15cm maximum total N concentration (0.083g 100g -1 ) was recorded in those treatments which were treated with (Filter cake+ full NPK) and statistically similar to those treatments which were received Tomato remains+ full NPK, MSW+ full NPK and similar trend was found for 15-30cm depth.The AB-DTPA extractable P (11.2 mg Kg -1 ) was observed higher in treatment (half NPK +Filter cake) at depths of 0-15cm and 15-30cm.High AB-DTPA extractable K (176.8 and 113.3 mg Kg -1 ) was recorded in the treatment (full NPK+ Filter cake) at two soil depths at 0-15 and 15-30cm respectively.The highest organic matter in the soil was observed (1.64 and 1.07 g 100g -1 ) in the treatment (full NPK +Filter cake) at soil depths at 0-15 and 15-30 cm simultaneously.At the depths of 0-15 cm and 15-30 cm the minimum concentrations of total N, AB-DTPA extractable P and K and soil organic matter were observed.The balance supply of the major three nutrients required for plant growth and development, there might be a significant increase in total N concentration [9].Influence of organic waste and NPK fertilizer on NPK concentration in potato tuber N-P-K fertilizers and organic waste significantly (P ≤ 0.05) increases NPK application in potato tuber as compared to control treatment.Statistically higher N concentration was perceived (2.10 g 100g -1 ) in treatment which received half NPK+ MSW and was different from rest of the treatments and lowest in control as shown in Table 3.The maximum P concentration (0.30 g100g -1 ) was recorded in treatment combination which was applied Filter cake +full NPK dose and lowest was recorded in control (0.19 g 100g -1 ).The K concentration was highest (3.16 g 100g -1 ) in treatment (half NPK +MSW) and lowest in control (2.0g100g -1 ).