Feldspar-K Fertilization of Potato (Solanum tuberosum L.) Augmented by Biofertilizer

American-Eurasian J. Agric. & Environ. Sci., 12 (6): 694-699, 2012 ISSN 1818-6769 IDOSI Publications, 2012 DOI: 10.5829/idosi.aejaes.2012.12.06.1802 Feldspar-K Fertilization of Potato (Solanum tuberosum L.) Augmented by Biofertilizer 1 2 M.A. Abdel-Salam and A.S. Shams 1 Department of Soil, Faculty of Agriculture (Moshtohor), Benha University, Egypt 2 Department of Horticulture, Faculty of Agriculture (Moshtohor), Benha University, Egypt Abstract: A field experiment was carried out at the Experimental Farm of the Faculty of Agriculture, Moshtohor, Benha University, Qalubiya Governorate, Egypt during the two successive seasons of 2010 and 2011 to investigate K fertilization by using feldspar-k and sulphate-k and biofertiliztion with a mixture of N-free fixing bacteria, P-dissolving bacteria and silicate dissolving bacteria on growth of potato (Solanum tuberosum L cv. Sponta). The experimental design was a randomized complete block, factorial in 3 replicates. Factors of the experiment and their treatments were as follows: (A)K-addition, five treatments :(A ) 100% dose sulphate- 1 K(SK), (A ) 75% dose as SK + 25% dose as feldspar-k(fk),(a ) 50% SK + 50% FK,(A ) 25% SK + 75% FK and 2 3 4 (A ) 100% dose of FK, the full dose of K was 300 kg K/ha,(B)Biofertilization, two treatments:(b ) no addition 5 0 of biofertilizer and (B ) addition of biofertilizer. Nitrogen and phosphorus were added to all treatments at a rate 1 of 350 kg N/ha and 75 kg P/ha. Plants were sprayed 3 times with Fe, Zn, and Mn-EDTA at rate of 0.5,0.2 and 0.15 kg/ha, respectively, at 55, 65 and 75 days after planting in each season. Treatment A gave the highest yield 3 (tubers and shoots), macro nutrient uptake (N, P and K) in tubers and shoots, tuber size, starch content, leaf area, and total chlorophyll. Increasing the dose of feldspar-k increased nitrate content in tuber. Biofertiliztion increased yield (tubers and shoots), macro nutrient uptake (N, P and K) in tubers and shoots, tuber size, starch content, leaf area, and total chlorophyll. It decreased slightly nitrate content in tubers. Key words:feldspar-k Biofertiliazer Potato Yield Macro nutrient uptake Tuber size Nitrate content leaf area INTRODUCTION Recently addition of these fertilizers has been criticized due to a suspicion of having an adverse effect on One of the most important solanaceous vegetable environment [10]. The alternative is to exploit other crops grown in Egypt is Potato (Solanum tuberosum L.). natural resources such K-bearing minerals which include Its tubers are rich in carbohydrates and contain K-feldspar, lecuite, K-mica (e.g. biotite, plogopite and considerable amounts of proteins, vitamins and minerals glauconite) and clays minerals such as illite [11]. These [1]. The cultivated area of potato in Egypt in season 2008 materials weather slowly thus replenish the native pool of was 84000 hectare (200.000 feddan) with total tuber yield available K, therefore acting as slow release K-fertilizers of 2.000.000 Mg with an average of 23.8 Mg/ha [2]. Potato [12-14]. The effectiveness of K-bearing minerals as has a high potassium requirement [3] that could be K-fertilizers in agriculture is low due to their slow attributed to: poorly developed root system [4, 5], availability [12, 14]. Some microorganisms play important potassium role in carbohydrate metabolism [6]. roles in the weathering processes of silicate minerals Potassium is necessary for many plant functions such as through solubilizing nutrients (including K) from these carbohydrate metabolism enzyme activation, osmotic minerals [15, 16]. Microorganisms which are commonly regulation, N uptake, protein synthesis, photosynthesis known as potassium solubilizing bacteria (KSP) or and translocation of assimilates [6-9]. Potassium is usually potassium dissolving bacteria (KDP) or silicate dissolving applied in forms of chemical fertilizers mainly sulphate, bacteria (SDP) solubilize K-bearing minerals to free K for chloride and nitrate [5]. In Egypt K is added as sulphate. plants. Corresponding Author: M.A. Abdel-Salam, Department of Soil, Faculty of Agriculture (Moshtohor), Benha University, Egypt. 694

The aim of the current study is to investigate the Horticulture Crops, Cairo, Egypt. Feldspar-K was response of potato (Solanum tuberosum L. cv. Sponta) obtained from by El-Ahram Company Cairo, Egypt, to K fertilization (combination of feldspar-k and containing 9.1% K%. Inoculants of the biofertilizer were sulphate-k) and biofertiliztion using N-free living bacteria, prepared by the Botany Department (Microbiology phosphate dissolving bacteria and silicate dissolving Branch), Faculty of Agriculture, Benha University, Egypt. bacteria. th Tubers were planted in the field on 28 of January in each season. With regard to tuber inoculation it was done by MATERIALS AND METHODS dipping them for 10 minutes in a suspension of the biofertilizers before planting. Nitrogen and phosphorus A field experiment was carried out at the Experimental were added to all treatments at a rate of 350 kg N/ha and Farm of the Faculty of Agriculture, Moshtohor, Benha 75 kg P/ha. Phosphorus and potassium were added during university, Qalubiya Governorate, Egypt during the land preparation. Nitrogen was added in weeks 4, 7 and 10 two successive seasons of 2010 and 2011 to investigate after planting (equal splits). Plants were sprayed 3 times K fertilization using feldspar-k and sulphate-k) and with Fe, Zn, and Mn EDTA at rate of 0.5,0.2 and 0.15 kg/ biofertiliztion with a mixture of N-free fixing bacteria, ha, respectively, at 55, 65 and 75 days after planting in P-dissolving bacteria and silicate dissolving bacteria on each season. Physical and chemical properties of the soil growth of potato (Solanum tuberosum L cv. Sponta). are presented in Table 1. Soil samples were collected from The experimental design was a randomized complete the 0-15cm surface layer. One composite representative block, factorial, in 3 replicates. Factors of the experiment sample was taken before conducting the experiment to and their treatments were as follows: (A)K-addition: five analyze soil of the field of the experiment. Four plants from treatments of :(1) 100% dose sulphate-k,(2) 75% dose as each plot were randomly taken to measure vegetative sulphate-k + 25% dose as feldspar-k,(3) 50% sulphate-k growth parameters 90 days after planting, plant samples + 50% feldspar-k,(4) 25% sulphate-k + 75% feldspar-k were oven-dried at 70 C then ground and kept for and (5) 100% dose feldspar-k (designated as K 1,K 2,K 3, analysis. Plants were harvested 110 days after planting and K 5, respectively), the full dose of K was 300 kg and tuber yield was recorded. Soil analyses included K/ha;(B)Biofertilization; two treatments :(1) no addition particle size distribution by the pipette method [17]. Other of biofertilizer(b 0) and (2) addition of biofertilizer(b 1). analyses included soil ph (in a 1:2.5 w: v soil: water The biofertilizer is a combined mixture of N-free fixing suspension), salinity of paste extract, total and available bacteria (Azotobacter and Azospirillium)+P-dissolving K (NH 4 OAc-extractable), organic matter and calcium bacteria (Bacillus megatherium) + silicate dissolving carbonate (by a calcimeter); methods of which are 2 bacteria (SDB) (Bacillus circulans). Plot size was 10.5 m described by Page et al. [18]. Plant samples were analyzed (3x3.5 m) with 25 cm between plants, each plot contained for N, P, K [19] and starch [20]. Nitrate content was 60 plants. Certified potato tubers were obtained from analyzed by Cataldo et al. [21] and total Chlorophyll the General Authority for Producers and Exporters of content by A.O.A.C. [22]. Table 1: Physical and chemical properties of the soil Characteristics Value Total K (g/kg) 4.21 available K* (g/kg) 0.39 EC (ds/m) in paste extract 0.82 ph (1:2.5 soil: water suspension.) 8.35 Calcium carbonate (g/kg) 29.1 Organic matter (g/kg) 14.2 Particle size-distribution (%): Coarse sand 4.7 Fine sand 16.0 Silt 34.6 Clay 44.7 Texture class Clay *available K (NH 4 Oac-extractable) 695

RESULTS AND DISCUSSION Macro Nutrient Uptake (N, P, K) by Plant Tubers: Potassium uptake by tubers was significantly increased Fresh Yield of Potato (Tubers and Shoots): Tuber fresh upon biofertilization, by an average of 6.4 % (Table 3). yield significantly increased due to biofertilization by an The highest K uptake occurred with K 3 treatment average of 1.8% (Table 2), a consequence of activities of followed by K 1, K 2, K 5 and K 4 in that descending order. N-fixing, K and P dissolving microorganisms that must The increase of K uptake due to K 3 over the other have increased availability of N, P and K [23]. K-addition treatments ranged between 26.2 to 62.1 %. Biofertilization treatments varied in their effect. The highest yield was increased K uptake particularly with K 1, K 2 and K 3, but obtained by K 3, which was significantly higher than with K 5, biofertiliztion significantly decreased K uptake. K 1, K 2, K 4 and K 5in that descending order. The increased Phosphorus uptake by tubers was significantly increased yield by the K 3 treatment over those by the other by biofertilization, giving an average of 12.2%. Regarding treatments ranged from 18.9 to 30.2%. Therefore, addition K-addition treatments, the highest P uptake occurred by of K as 50% soluble-k + 50% feldspar-k seemed to have K 3 treatment followed by K 1, K 2, K 5 and K 4 in that been the most efficient ratio for providing sufficient K for descending order. The increase of P uptake by K 3 over the plants, as it had the highest K uptake in both tuber and other treatments ranged between 31.6 to 102.2 %. shoot. Although K 5(feldspar-K) gave the lowest tuber Biofertilization increased P uptake particularly with and yield, increases over it by K 4,K 2 and K 1 treatments were treatments while with K 4 and K 5 treatments not marked being 2.3,4.3 and 9.5 %,respectively. The biofertiliztion significantly decreased P uptake. Under treatment surpassed by 30 %. Biofertilization was condition of no biofertilization, the highest P uptake was effective in increasing the efficiency of added K by K 5 treatment followed by K, 1K, 3K 2and K in4 particularly where the source was 100 % soluble descending order. Nitrogen uptake by tuber was sulphate-k (K 1); presence of sufficient amount of significantly increased upon biofertilization, by an available K for growth of both microorganism and plant average of 5.6%. Regarding K-addition treatments the could explain that [24]. Shoot yield showed the same trend highest N uptake occurred with K 3 treatment followed by of the tubers such as that as biofertilization significantly K 1, K 2, K 5 and K 4 in that descending order. The increase increased the yield, 2.1%. K-addition treatments varied of N uptake due to K 3 over other treatments ranged in their effect. The highest yield was given by between 22.8 to 63.3 %. Biofertilization increased N uptake followed by K 1, K 2, K 4 and K 5 in that descending order. particularly with the K 1, K 3and K 4treatments, but with the The increased yield by the treatment over the other K 5 treatment, biofertiliztion significantly decreased N treatments ranged from 31.2 to 62.3 %. Biofertiliztion uptake. significantly increased the yield in treatments K 1, K 4 and The uptake of N, P and K showed patterns which K 5 while with and K 3 it did not show a significant were rather similar to those of the yield. The highest was effect. by K 3 treatment followed by K 1, K 2, K 5 and K 4 in that K-addition; K 1:100% of sulphate-k (SK), K 2 75% descending order. This reflects increased K availability. SK + 25% feldspar-k (FK), K 3: 50% SK + 50% FK, K 4: 25% Potassium enhances plant growth and consequently SK + 75% FK, K 5: 100% FK, K full dose 300kg K/ha. increases uptake of nutrients [25]. The increase in Biofertilizer; B 0: no biofertilizer, B 1: added biofertilizer available K would be accompanied by high nutrient (mixed bacteria). uptake. The significant decrease of N, P and K uptake by Table 2: Effect of K-addition and biofertilization on fresh yield of potato tubers and shoots ---------------------------------------- ----------------------------------------- Treatments B0 B1 B0 B1 K-addition(K) Fresh yield (tubers) Mg/ha Fresh yield (Shoots)Mg/ha 28.85 30.56 29.70 13.45 13.89 13.67 28.18 28.44 28.31 13.27 12.92 13.09 35.22 35.42 35.32 17.85 18.01 17.93 27.51 27.99 27.75 11.48 12.00 11.74 27.11 27.13 27.12 10.78 11.33 11.05 29.37 29.91 -- 13.36 13.63 -- LSD 5% K : 0.48 B : 0.30 KB : 0.68 K : 0.30 B : 0.18 KB : 0.42 696

Table 3: Effect of K-addition and biofertilization on nutrient uptake (N, P, K) by plant tubers. ----------------------------- ---------------------------- ------------------------------ Treatments B0 B1 B0 B1 B0 B1 K-addition(K) N uptake(tuber) kg /ha P uptake(tuber) kg /ha K uptake(tuber) kg /ha 73.76 76.48 75.12 13.32 15.43 14.38 212.32 234.83 223.57 57.47 58.52 58.00 11.61 11.72 11.66 189.03 194.84 191.94 83.24 101.33 92.28 11.80 26.06 18.93 260.12 304.47 282.30 53.48 59.52 56.50 10.58 8.16 9.37 171.99 176.29 174.14 63.13 53.78 58.45 15.89 11.29 13.59 184.31 173.35 178.83 66.22 69.93 -- 12.64 14.18 203.55 216.75 -- LSD 5% K:1.27 B:0.80 KB:1.80 K : 0.23 B:0.14 KB:0.32 K:4.10 B:2.59 KB:5.80 K-addition; K :100% of sulphate-k(sk), K 75% SK + 25% feldspar-k(fk), K : 50% SK + 50% FK, K : 25% SK + 75% FK, K : 100% FK, K full dose 1 2 3 4 5 300kg K/ha. Biofertilizer; B : no biofertilizer, B : added biofertilizer (mixed bacteria) 0 1 Table 4: Effect of K-addition and biofertilization on nutrient uptake (N, P, K) by plant shoots --------------------------- --------------------------- ----------------------------- Treatments B0 B1 B0 B1 B0 B1 K-addition (K) N uptake(shoot) kg/ha P uptake(shoot) kg/ha K uptake(shoot) kg/ha 38.67 41.00 39.84 3.46 4.63 4.04 83.68 88.84 86.26 36.26 35.55 35.91 3.15 3.15 3.15 80.44 80.58 80.51 48.31 52.75 50.53 5.00 5.65 5.32 94.94 97.48 96.21 28.45 33.05 30.75 2.38 2.71 2.54 65.40 73.51 69.46 24.23 28.08 26.16 2.27 2.45 2.36 60.47 66.06 63.27 35.19 38.08 -- 3.25 3.72 -- 76.98 81.30 -- LSD 5% K: 2.1 B:1.37 KB: NS K:0.21 B:0.13 KB:0.30 K:4.72 B:2.98 KB: NS K-addition; K :100% of sulphate-k(sk), K 75% SK + 25% feldspar-k(fk), K : 50% SK + 50% FK, K : 25% SK + 75% FK, K : 100% FK, K full dose 1 2 3 4 5 300kg K/ha. Biofertilizer; B : no biofertilizer, B : added biofertilizer (mixed bacteria) 0 1 tubers due to biofertilization under condition of K 5 could feldspar-k dose in K-addition led to a rise in nitrate be attributed to a possible slow K release from feldspar-k concentration particularly with K 5 (which is 100% being not sufficient for the growth of both feldspar-k).this could be a result of nitrate metabolism as microorganisms and plant [23]. nitrate accompanied by sulphate-k (soluble-k) being metabolized, faster than, when accompanied by feldspar-k Macro Nutrient Uptake (N, P, K) by Plant Shoots: As in (slow release-k). Potassium would attract greater amounts fresh yield of tubers and shoots, biofertilization of anions (including nitrates) as a consequence of its significantly increased K, P and N uptake by shoots, by enzyme activation role [26]. There was slight though not an average of 5.6, 14.6 and 8.2 % for each nutrient, significant decrease due to biorfertilization. There was respectively (Table 4). The highest N, P and K uptake no significant interaction between biofertilization and occurred with K 3 treatment followed by K 1, K 2, K 4and K-addition. Starch content in tuber was significantly in that descending order. The higher nutrient uptake due increased due to biofertilization, by an average of 2.9 %. to over the other treatments ranged between, 11.5 to The highest starch content occurred with the K 3 treatment 52.1% in K uptake, 31.6 to 125.4% in P uptake and 26.8 to followed by K 1, K 2, K 4 and K 5 in that descending order. 93.1 % in N uptake. The highest starch content due to K 3 treatment over the There was no significant interaction between other treatments ranged between 1.6 to 17.3 %. K-addition and biofertilization on N and K uptake by Biofertilization increased starch content with K 1 and shoots. Biofertilization caused an increase in P uptake treatments and slightly increased it with K 2 and K 5 and except where and K 5 treatments were applied no decreased it with K 3 treatment. With biofertilization the effectiveness occurred due to biofertilization. highest starch content was caused by K 1 treatment followed by K 3, K 2, K 4 and K 5 in descending order. Tuber Size and Content of Nitrate and Starch in Tuber: Potassium plays an important role in carbohydrate Nitrate content in tuber showed significant variations translocation from leaves to tubers [1] thus the higher among K-addition treatments (Table 5). Increasing the starch content in K is an evidence of high available 697 3

Table 5: Effect of K-addition and biofertilization on size, nitrate concentration and starch content in tuber -------------------------- --------------------------- ------------------------------ Treatments B0 B1 B0 B1 B0 B1 K-addition(K) Nitrate content in tuber mg/kg Starch content in tuber g/kg Tuber size (cm 3 ) 271 264 268 266.07 275.27 270.67 184.42 193.00 188.71 291 280. 286 264.73 265.63 265.18 179.67 180.00 179.84 297 297 297 274.93 274.87 274.90 198.33 194.67 196.50 305 303 304 236.00 263.53 249.77 170.67 175.67 173.17 311 306 309 234.17 234.33 234.25 151.33 151.67 151.50 295 290 -- 255.18 262.73 176.88 179.00 -- LSD 5% K:22.0 B: NS KB: NS K: 4.66 B: 2.94 KB: 6.59 K:3.10 B:1.96 KB:4.39 K-addition; K :100% of sulphate-k (SK), K 75% SK + 25% feldspar-k (FK), K : 50% SK + 50% FK, K : 25% SK + 75% FK, K : 100% FK, K full dose 1 2 3 4 5 300kg K/ha. Biofertilizer; B : no biofertilizer, B : added biofertilizer (mixed bacteria) 0 1 Table 6: Effect of K-addition and biofertilization on Leaf area and total chlorophyll in fresh weight ------------------------------------------ ----------------------------------- Treatments B0 B1 B0 B1 2 K-addition(K) Leaf area (cm ) Total chlorophyll in fresh weight (g /kg) 1892.3 1970.5 1931.4 1.78 1.80 1.79 1661.0 1861.2 1761.1 1.54 1.60 1.57 2056.1 2341.9 2199.0 1.77 1.81 1.79 1540.5 1591.9 1566.2 1.42 1.49 1.45 1250.7 1426.1 1338.4 1.40 1.41 1.41 1680.1 1838.3 1.58 1.62 LSD 5% K : 13.4 B: 8.4 KB :18.9 K : 0.04 B: 0.03 KB :NS K-addition; K 1:100% of sulphate-k (SK), 75% SK + 25% feldspar-k(fk), K 3: 50% SK + 50% FK, K : 4 25% SK + 75% FK, K : 5100% FK, K full dose 300kg K/ha. Biofertilizer; B 0:no biofertilizer, B 1: added biofertilizer (mixed bacteria) K with treatment. Tuber size significantly increased due Leaf area and chlorophyll content plays an important role to biofertilization, by an average of 1.2 %. The highest in photosynthesis and metabolism of carbohydrate and tuber size occurred in K 3 treatment followed by K 1, K 2, protein [27], this indicates that high carbohydrate and K 5 in that descending order. The highest tuber size formation took place under conditions of K 3 and K 1. due to K 3 treatment over the other treatments ranged Potassium affects translocation of carbohydrates form between 4 to 30 %. There was no significant decrease in leaves to tubers [1] and with K 3 it gave the highest K tuber size due to biofertilization in K treatment. uptake (tuber and shoot). Such conclusion is confirmed 3 Leaf area and Total Chlorophyll in Fresh Weight: As in macro nutrient uptake (N, P and K) by plant shoots, leaf area was significantly increased due to biofertilization, by results of starch content which was highest with K 3 (Table 5). CONCLUSIONS by 9.4 %. The highest leaf area occurred with the K 3 treatment followed by K 1, K, 2 K 4and K in 5 that The most effective combination of sulphate-k and descending order. The highest leaf area due to feldspar-k as a K source for potato on clay soil was 50% treatment over the other treatments ranged between 13.8 as sulphate-k + 50% as feldspar-k. This was shown to 64.3 %. Total chlorophyll in fresh plant material positively on tuber size and yield. This result is confirmed increased due to biofertilization, by an average of 2.5 by the increase of macro nutrient uptake (N, P and K) in %.The highest total chlorophyll occurred in both K 1 and tubers and shoots as well as leaf area, starch content and treatments followed by K, K 2 and 4 K in 5 that total chlorophyll. Increasing the dose of feldspar-k descending order (Table 6). The increase in total increased nitrate content in tuber. Biofertiliztion of potato chlorophyll due to K 1 and K 3 treatments over the other grown on the clay soil increased yield (tubers and treatments ranged between 14.0 to 26.9 %. Potassium shoots), macro nutrient uptake (N, P and K) in tubers and positively increases leaf area and chlorophyll content shoots as well as tuber size, leaf area, and total indirectly through influencing growth hormones [27]. chlorophyll. It decreased slightly nitrate content in tubers. 698

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