Friday, November 11, 2016

EFFECT OF ORGANIC AND INORGANIC MANURES ON YIELD PERFORMANCE OF STRAWBERRIES GROWN UNDER THE SUB-TROPICAL CONDITION OF SRI LANKA

P.D.Abeytilakarathna1 , R.M.Fonseka2 and J.P.Eswara2

1 Regional Agriculture Research and Development Center, Bandarawela, Sri Lanka.
2  Faculty of Agriculture, University of Peradeniya, Sri Lanka


ABSTRACT

An experiment was conducted in the Agriculture Research Station at Rahangala, aim to evaluate the effect of organic and inorganic fertilisers on growth and yield performance of Strawberry cultivation under the sub-tropical condition in Sri Lanka. The specific objectives of this study are, (i) to reduce Department of Agriculture (DOA) recommended inorganic fertilizer rate without affecting the yield and quality using compost and titonia green manure and (ii) study the effect of organic and inorganic fertilizers on fruits quality and yield of strawberries

The growth and yield performance of strawberry variety “Chandler” was investigated by using nine different combinations of tithonia green manure and compost with urea and muriate of potash (MOP). Experiment was laid out as a Randomized Complete Block Design (RCBD) with 3 replicates. Strawberry sets were planted in the open field (plot size is 3 x 2 m) with 30 x 40 cm spacing. DOA recommended amount of triple super phosphate (TSP), agrochemicals and other cultural practices were used.

Weight of all berries, marketable berries and nonmarketable berries were not significantly different during, when reduction of the DOA recommended  rate of  urea and MOP by 25%, 50%, 75% ,100 % while increasing tithonia at the rate of 2, 4, 6, 8 t/ ha respectively or compost at the rate of 2, 3, 4, 5 t /ha respectively. These combinations of inorganic fertilizers and compost or tithonia did not affect to the average berry weight, number of inflorescences per plant  and the brix value of ¾ coloured strawberry fruits.

Key words: Compost, Muriate of potash, Strawberry, Tithonia, Urea.


INTRODUCTION

The use of inorganic fertilizer is high in the North Central province followed by North Western, Uva and Eastern provinces due to the higher extent of land under cultivation. Approximately 600,000 t of solid fertilizers and 250,000 l of liquid fertilizers are imported to Sri Lanka annually (Weerarathna, 2014). In year 2012, 0.30 million tons of Urea, 0.11 million tons of TSP, 0.10 million tons of MOP and 0.08 million tons of Ammonium sulphate were imported to Sri Lanka (Weerarathna, 2014).

 Strawbery plants tend to grow out of the ground and develops poor root-soil contact with age (Ellis et al., 2006) and dry soil causes dying of new roots or root tips that are arisen from the crown of strawberry plant (White, 1929). Therefore, mulching with straw and incorporation of compost to the soil are required to conserve soil moisture and soil structure that hasten the growth of roots. Strawberry plants feeds with more nitrogen and potassium caused to increase number of runner production and decrease the yield due to reduce the inflorescences number (Ellis et al., 2006).  Therefore, it is important to reduce the inorganic fertilizer while increasing the organic manures.


MATERIALS AND METHODS

Effect of 9 different combinations of tithonia green manure and compost with urea and MOP (Table 3) on the growth and yield performance of strawberry variety “Chandler” was investigated. Experiment was laid out as a randomized complete block design (RCBD) with 3 replicates. Strawberry sets were planted in open field. Plots size was 3 x 2 m and plating space was 30 x 40 cm. DOA recommended amount of triple super phosphate (TSP) and agrochemicals were used.

Four soil samples at a depth of 0–15 cm were collected at different points from a block of the experimental field before planting. The samples were bulked, air-dried and screened through a 2 mm sieve. The soil pH was determined with the pH meter. Exchangeable K was determined using flame photometer after the soil samples were extracted in 1 M neutral ammonium acetate (NH4OAC). The total nitrogen in soil and compost was determined by the Kjeldahl method. Available phosphorus was determined by using spectrophotometer at 470 nm after extracting in 0.03 M ammonium fluoride and 0.025 M HCl (Bray and Kurtz, 1945). Organic matter percentage was determine ignition method (soil samples were kept in dry oven at 105 0C temperature for 4 hours, followed by 4 hours kept in muffle furnace at 400 0C temperature (Table 1). Proximate analysis of the strawberry and  Tithonia leaves for NPK content was carried out using standard method (dry ash method for P & K, Kjeldhal method for N) (Table 2). Tithonia diversifolia (fresh leaves and soft stems) was chopped before use. Brix value of fruits was measured by using brix meter.

Table 1.   Soil chemical properties of the field at ARS, Rahangala during the years of 2013 and 2014.


Soil chemical property

Year 2013

Year 2014
pH (1:1 soil: water )
Total N %
Bray P (ppm)
Exchangeable K (ppm)
Organic matter %
5.8
0.12
10.5
112
2.1
5.7
0.11
11.2
117
2.1



Table 2.   Chemical properties of compost and tithonia used for strawberry trial at ARS, Rahangala during the years of 2013 and 2014.



Chemical property

Year 2013

Year 2014

Compost

Tithonia

Compost

Tithonia
N %
P %
K%
1.20
0.30
3.80
1.60
0.10
0.07
1.40
0.40
4.3
1.50
0.14
0.09



Table 3.   Basal and top dressing fertilizer levels used in different treatments for strawberries during 2013-2014.



Treatments
Basal dressing kg/ha
Top Dressing kg/ha
2 & 3 MAP
6 MAP
8 MAP
T1
DOA recommended inorganic fertilizer (100% urea, TSP & MOP)
Urea 80, TSP 160, MOP 40
Urea 80, MOP 40
Urea 60, TSP 80, MOP 40 
Urea 60, MOP 40
T2
75 % of urea & MOP, 100% TSP & Tithonia 2 t/ha
Urea 60, TSP 160,  MOP 30, Tithonia 500
Urea 60,   MOP 30, Tithonia 500
Urea 45, TSP 80,  MOP 30, Tithonia 500
Urea 45,  MOP 30, Tithonia 500
T3
50 % of urea & MOP, 100% TSP & Tithonia 4 t/ha
Urea 40, TSP 160,  MOP 20, Tithonia 1000
Urea 40,   MOP 20, Tithonia 1000
Urea 30, TSP 80,  MOP 20, Tithonia 1000
Urea 30,  MOP 30, Tithonia 1000
T4
25 % of urea & MOP, 100% TSP & Tithonia 6 t/ha
Urea 20, TSP 160,  MOP 10, Tithonia 1500
Urea 20,   MOP 10, Tithonia 1500
Urea 15, TSP 80,  MOP 10, Tithonia 1500
Urea 15,  MOP 10, Tithonia 1500
T5
0  % of urea & MOP, 100% TSP & Tithonia 8 t/ha
TSP 160, Tithonia 2000
Tithonia 2000
TSP 160, Tithonia 2000
Tithonia 2000
T6
75  % of urea & MOP, 100% TSP & Compost 2 t/ha
Urea 60, TSP 160,  MOP 30, Compost 20t
Urea 60,   MOP 30,
Urea 45, TSP 80,  MOP 30,
Urea 45,  MOP 30,
T7
50  % of urea & MOP, 100% TSP & Compost 3 t/ha
Urea 40, TSP 160,  MOP 20, Compost 30 t
Urea 40,   MOP 20,
Urea 30, TSP 80,  MOP 20,
Urea 30,  MOP 30,
T8
25  % of urea & MOP, 100% TSP & Compost 4 t/ha
Urea 20, TSP 160,  MOP 10, Compost 40 t
Urea 40,   MOP 20,
Urea 30, TSP 80,  MOP 20,
Urea 45,  MOP 30,
T9
0  % of urea & MOP, 100% TSP & Compost 5 t/ha
TSP 160, Compost 50 t
-
TSP 160
-
MAP- months after planting


Data collection and analysis

Growth, yield and quality parameters such as weight of all berries per plant, weight of marketable barriers per plant, weight of nonmarketable berries per plant, average fruit weight,  number of crowns, number of runners, number of inflorescences, total solid content of ¾ coloured fruits. N, P, K , pH  were recorded. Percentage of organic matter of compost and soil were measured at the beginning and end of the experiment. Data were subjected to statistical analysis using AssiStat version 7.6 beta (2012) and R version 3.1.2 software.

 Fig 1.   Field layouts of strawberry field trials at Agricultural Research Station of  Rahangala during (a) 2013 and (b) 2014.


  Fig 2.  Strawberry fruiting crop (a) at flowering stage and (b) red coloured primary fruit, immature secondary and tertiary berries in fruit bearing stage.




Fig. 3.   Incorporation of tithonia for strawberry (a) before planting and (b) after planting. Tithonia (c) tender stems and leaves and (d) chopping of tender stems


RESULTS

Yield performance of strawberries
The DOA recommended inorganic fertilizer and 25%, 50%, 75% ,100 % reduction of recommended rates of urea and MOP along  with incorporation of tithonia 2. 4, 6, 8 t/ha respectively or compost 2, 3, 4, 5 t /ha respectively were observed statistically similar yields for all berries, marketable berries or nonmarketable berries during both years of 2013 and 2014 (Table 4). Furthermore, the weight of total berries, marketable berries and non-marketable berries obtained during year 2014 was higher than the year 2013.
 
Table 4.   Yield of strawberry grown with different level of urea, MOP, tithonia and compost during 2013-2014.

Treatments
Yield (g/plant) during 2013
Yield (g/plant) during 2014
Marketable berries NS
Non marketable berries NS
All berries NS
Marketable berries NS
Non marketable berries   NS
All berries NS
DOA recommended inorganic fertilizer (T1)
27.8
12.8
40.6
31.6
13.4
45.0
75 % of urea & MOP, & Tithonia 2 t/ha (T2)
24.7
14.3
38.9
32.8
10.0
42.0
50 % of urea & MOP, & Tithonia 4 t/ha (T3)
20.8
9.7
30.5
25.2
9.5
34.6
25 % of urea & MOP & Tithonia 6 t/ha (T4)
28.0
13.3
41.2
46.3
17.9
64.2
0  % of urea & MOP & Tithonia 8 t/ha (T5)
27.4
12.8
40.2
40.6
15.6
56.2
75  % of urea & MOP & Compost 2 t/ha (T6)
20.8
14.1
34.9
54.7
13.4
68.1
50  % of urea & MOP & Compost 3 t/ha (T7)
31.5
16.2
47.6
46.3
15.4
61.8
25  % of urea & MOP & Compost 4 t/ha (T8)
20.4
9.9
30.2
45.0
16.5
61.5
0  % of urea & MOP & Compost 5 t/ha (T9)
15.5
9.6
25.1
30.8
12.7
43.5
CV%
67.4
53.6
61.1
32.6
34.3
31.7
NS –Not significant at p=0.05


Yield component of strawberries

Average fruit weight of strawberries
Every increment of compost by 1 t/ha from 2 t/ha basal dressing or increasing the tithonia by way of 2 t/ha for every 25 % reduction of recommended amount of urea and MOP were not affected to average fruit weight of strawberries (Table 5).

Table 5. Average berry weight of strawberry grown with different level of urea, MOP, tithonia and compost during 2013-2014


Treatments
All berries
2013
2014
Log transformed NS
Average weight (g)
Log transformed NS
Average weight (g)
DOA recommended inorganic fertilizer (T1)
0.7953
5.3
0.8797
6.6
75 % of urea & MOP & Tithonia 2 t/ha (T2)
0.8365
6.0
0.9020
7.0
50 % of urea & MOP & Tithonia 4 t/ha (T3)
0.8522
6.1
0.8544
6.2
25 % of urea & MOP & Tithonia 6 t/ha (T4)
0.8782
6.6
0.8576
6.3
0  % of urea & MOP & Tithonia 8 t/ha (T5)
0.7680
4.9
0.9505
8.0
75  % of urea & MOP & Compost 2 t/ha (T6)
0.8454
6.0
0.8994
6.9
50  % of urea & MOP & Compost 3 t/ha (T7)
0.7755
5.0
0.9479
7.9
25  % of urea & MOP & Compost 4 t/ha (T8)
0.8378
6.0
0.9055
7.1
0  % of urea & MOP & Compost 5 t/ha (T9)
0.7402
4.6
0.9188
7.3
CV%
7.6
-
5.6
-
NS- Not significant at p=0.05

Numbers of inflorescences
Statistically, same number of inflorescences per plant of strawberry were observed when increasing compost by 1 t/ha from the basal dressing of 2 t/ha or increasing the tithonia by 2 t/ha along with reduction of urea and MOP by 25 % (Table 6).

Table 6  Average number of inflorescences of strawberry grown with different level of urea, MOP, tithonia and compost during 2013-2014.

Treatments
Average number of inflorescences/plant
2013
2014
Log transformed NS
Untransformed
Log transformed NS
Untransformed
DOA recommended inorganic fertilizer (T1)
0.2299
0.7
0.2341
0.7
75 % of urea & MOP & Tithonia 2 t/ha (T2)
0.3308
1.2
0.3089
1.1
50 % of urea & MOP & Tithonia 4 t/ha (T3)
0.3192
1.1
0.3245
1.2
25 % of urea & MOP & Tithonia 6 t/ha (T4)
0.2709
0.9
0.2651
0.9
0  % of urea & MOP & Tithonia 8 t/ha (T5)
0.2732
1.1
0.2364
0.7
75  % of urea & MOP & Compost 2 t/ha (T6)
0.2996
1.0
0.3735
1.4
50  % of urea & MOP & Compost 3 t/ha (T7)
0.4327
1.7
0.1755
0.6
25  % of urea & MOP & Compost 4 t/ha (T8)
0.4025
1.5
0.2502
0.8
0  % of urea & MOP & Compost 5 t/ha (T9)
0.1693
0.6
0.2535
0.8
CV%
42.2
-
44.9
-
NS- Not significant

Effect of different treatments on soil N P K
The soil nitrogen percentages at the end of harvesting season of strawberry were not significantly difference with the different treatments during the year 2013. But there was a significant difference of nitrogen at p=0.01 during the year 2014. Incorporation of tithonia at the rate of 2 to 8 t/ ha were seen higher soil nitrogen than the addition of compost at the rate of 2 to 5 t/ha (Fig. 4).

A significantly higher Bray phosphorous was also found in the treatment which was incorporated tithonia at the rate of 8 t/ha (6.6 ppm Bray P) and the lowest P was observed in the treatments that was incorporated compost at the rate of 3 t/ha (4.8 ppm Bray P) during the year 2013. However, there was not any significant difference of soil P during the year 2014 (Fig. 5). The highest soil potassium which significant at p=0.01, were found in the treatment of DOA recommended inorganic fertilizer both during 2013 and 2014 ( 132.3 and 133.3 ppm of K respectively).  The lowest K was seen in the treatments of compost at the rate of  5 t/ha and 25 % urea and MOP + compost 4 t/ ha during both years of 2013 (82 and 81 ppm K respectively)  and 2014 (89 and 86 ppm of K respectively) (Fig. 6).


Fig. 4. Soil nitrogen percentages of different treatments measured at the end of harvesting season of strawberry of the years of 2013 & 2014



 Fig. 5.   Soil phosphate of different treatments measured at the end of harvesting season of strawberry of the years of 2013 & 2014


Fig. 6.   Soil potash of different treatments measured at the end of harvesting season of strawberry of years of 2013 & 2014

Total solid content of strawberry fruits
The brix value of ¾ coloured strawberry fruit were not changed with increasing compost by 1 t/ ha after adding 2 t/ ha as basal dressing or  tithonia by 2 t/ha with reducing recommended urea and MOP by 25 %  (Table 7).

Table 7. Total solid contents of strawberry grown with different level of urea, MOP, tithonia and compost during 2013-2014

Treatments
Total solid content of fruits
2013
2014
Log transformed NS
0Brix
Log transformed NS
0Brix
DOA recommended inorganic fertilizer (T1)
0.7953
5.3
0.8797
6.6
75 % of urea & MOP & Tithonia 2 t/ha (T2)
0.8365
6.0
0.9020
7.0
50 % of urea & MOP & Tithonia 4 t/ha (T3)
0.8522
6.1
0.8544
6.2
25 % of urea & MOP & Tithonia 6 t/ha (T4)
0.8782
6.6
0.8576
6.3
0  % of urea & MOP & Tithonia 8 t/ha (T5)
0.7680
4.9
0.9505
8.0
75  % of urea & MOP & Compost 2 t/ha (T6)
0.8454
6.0
0.8994
6.9
50  % of urea & MOP & Compost 3 t/ha (T7)
0.7755
5.0
0.9479
7.9
25  % of urea & MOP & Compost 4 t/ha (T8)
0.8378
5.9
0.9055
7.1
0  % of urea & MOP & Compost 5 t/ha (T9)
0.7402
4.6
0.9188
7.3
CV%
7.6
-
5.6
-
 Ns- not significant at p=0.05


DISCUSSIONS

Nitrogen requirement for strawberry are 166 kg/ha (Albergts and Howard, 1982)  or  168 kg/ha (DOA, 2010) for the total season (200 days). Growers should avoid the temptation to apply of more nitrogen because excess nitrogen can increase the amount of malformed fruits (Albergts and Howard, 1982) and lead to excessive vegetative plant growth and reduce yield. The maximum annual incorporation of organic fertilizer to the amount of 170 kg/ha nitrogen due to excessive use of organic fertilizers can lead to adverse effects such as nitrogen leaching in to ground water, release of heavy metal and harmful organic substances in to soil, spread of weeds, soil pollution with harmful microorganisms etc.  (Council of Directive, 1991). Nitrogen 1.3% and potassium 4.1% were contained in the compost while nitrogen 1.6% and potassium 0.1 % were contained in the leaf and tender stems of tithonia (Table 2) on dry matter basis. According to Jama et al., (2000), the green leaf biomass of tithonia was high in nutrient, average about 3.5% N, 0.37 % P and 4.1 % K on dry matter basis. The advantage of incorporating tithonia biomass was the rapid decomposing after application to the soil and incorporating biomass can be effective for source of N, P, K for crops. Because of high labour requirements for cutting & carrying the biomass to field, the use of tithonia biomass as a nutrient source is more profitable with high value crops like strawberries (Jama et al., 2000). Ikerra et al., (2006), noted that the yield of corn grains was increased significantly with the application of 5 t/ha of this green manure. Similar effect was found in Asian rice Jama et al., 2000.  In both cases authors associated the beneficial effect of this manure with increments produced by it on the pH and on the exchange calcium, as well as with the decline of exchangeable aluminum and with the absorption capacity of phosphorus in the soil. The beneficial effect of green manures on improvements of the soil properties and on rice areas were indicated by Kumar et al., (2003). These authors attributed it mainly to the beneficial effect of the green manures on the percentage of stable aggregates to the water and to the increase of the organic matter content. Tithonia biomass was also recognized as an effective source of nutrient resulting in improved yield of Brassica oleraceae in nitrogen limiting soil (Onyango and Onyango, 2002).

DOA recommended rate of inorganic fertilizers give nitrogen at the rate of 168 kg /ha and potassium at the rate of 99.6 kg/ha (Table 3). When reducing the DOA recommended urea and MOP by 25%, 50% and 100%; nitrogen was received 126, 84, 42 and zero kg/ha and potassium was received 74.7, 49.8, 24.9 and zero kg/ha respectively. In our treatments, the DOA recommended urea and MOP were reduced by way of 25%, 50%, 75% ,100 % with adding tithonia 2, 4, 6, 8 t/ha or compost 2, 3, 4, 5 t /ha respectively. This combination of urea and tithonia were caused to receive the total nitrogen by 6.5, 13.1, 19.6 and 26.2 relative percentage respectively lower than the DOA recommended rate. Potassium was received by 23.2, 46.4, 69.6 and 92.8 relative percentages respectively. This lower than the DOA recommended rate of potassium from the combination of MOP and tithonia. The combination of reducing MOP while increasing compost were caused to increase the addition of extra potassium by 8.3, 72, 87.7 and 103.3 relative percentage than the DOA recommendation. But the combination of reducing urea while increasing compost was resulted reduce nitrogen receiving by 9.5, 26.8, 44 and 61.3 relative percentage than DOA recommendation. Wen et al., (1997) also stated that the application of compost had a positive effect on the concentration of available potassium.

When consider the yield and yield components, the  DOA recommended inorganic fertilizer and urea and MOP by way of 25%, 50%, 75% ,100 % reduction from recommended amount incorporating with tithonia 2. 4, 6, 8 t/ha respectively or compost 2, 3, 4, 5 t /ha respectively produce similar yields for  all berries, marketable berries or nonmarketable berries during both years of 2013 and 2014  (Table 4) and the total, marketable and non marketable yields obtained during year 2014 was higher than the year 2013. This combination of inorganic fertilizers and compost or tithonia did not effect to the average berry weight (Table 5), number of inflorescences per plant (Table 6) and the brix value of ¾ coloured strawberry fruits.

Triple super phosphate at the rate of 240 kg/ha (48.6 kg P /ha) were applied according to the DOA recommendation (2010) for all the treatments combinations (Table 3).  But Compost had 0.35 % P and Tithonia had a 0.12 % P (Table 2). Therefore when addition of tithonia the rate of 2, 4, 6 and 8 t/ ha, the extra P was added by 4.9, 9.9, 14.8 or 19.8 relative percentage respectively than the DOA recommendation while addition of  compost at the rate of 2, 3, 4 and 5 t /ha was caused to add extra P by 14.4, 21.6, 28.8 or 36 relative percentage respectively than the DOA recommendation. Reduction of recommended urea and MOP by 25 %  while increasing compost by 1 t/ha after adding 2 t/ha at the time of plant establishment or increasing tithonia by 2 t/ ha did not effect brix value of ¾ coloured strawberry fruit.


CONCLUSIONS

Strawberry yield did not reduced significantly with the reduction of DOA recommended urea and MOP by way of 25%, 50%, 75% ,100 % along with addition of  tithonia 2, 4, 6, 8 t/ ha or compost 2, 3, 4, 5 t / ha respectively. Therefore, 25% inorganic fertilizer could be reduce from recommended rate of urea and MOP by adding tithonia or compost at the rate of 2 t/ha.


REFERENCES

Albregts, E.E. and C.M. Howard (1982). Effect of fertilizer rate on number of malformed strawberry fruit. Proceeding of Florida State Horticultural Society, 95: 323-324.
Council Directive (1991). Concerning the protection of water against pollution caused by nitrated from agriculture sources. 91/676/EEC of 12 December 1991.
DOA, (2010). Strawberry. Fertilizer recommendation for horticultural crops Department of Agriculture ,Peradeniya. pp86
Ellis, M.A., R.C.Funt, S.Wright, K. Demchak, E. Wahle, D. Doohan, C.Welty, R.N.Williams and M.Brown, (2006) (Editors). Midwest strawberry production guide, The Ohio State university extension, Columbus, OH.
Ikerra,S., E. Semu and J. Mrema (2006). Combining Tithonia diversifolia and minjingu phosphate rock for improvement of P availability and maize grain yield on a chromic acrisol in Morogoro, Tanzania. Nutrient Cycling in Agro ecosystems, 76:249.
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Kumar, U., G. Singh, U.S. Victor and K.L. Sharma, (2003). Green manuaring: Its effect on soil properties and crop growth under rice-wheat cropping system. European Journal of Agronomy. 19: 225.
Onyango, A.M.O. and J.C. Onyango (2002). Influence of organic sources of fertilizer on growth and leaf yield of kole. Journal of Agriculture, Science and technology, 4 (1).
Weeraratna, C.S., (2014). Fertilizer use in Sri Lanka with special reference to Chronic Kidney. [Accessed on 04.07.2014]. Available at  http://nas-srilanka.org/wp-content/uploads/2013/01/Weeraratne-edited.pdf
Wen, G., J.P. Winter, R.P. Voroney and T.E. Bates (1997). Potassium availability with application of sewage sludge and sludge and manure compost in field experiments. Nutrient Cycling in Agro ecosystems, 47:233-241

White, P.R., (1929). Studies of the physiological anatomy of the strawberry. Journal of Agricultural Research. 35:481-492