FERTILIZATION MANAGEMENT BASED ON SOIL
SALINITY LEVEL ON FOUR (4) SUCCESSIVE
GREENHOUSE CUCUMBER CROPS

Nikolaos Gougoulias, Nicolas Chouliaras, Alexandros Papachatzis, Nikolaos

Chouliaras

► To cite this version:

Nikolaos Gougoulias, Nicolas Chouliaras, Alexandros Papachatzis, Nikolaos Chouliaras. FERTILIZATION MANAGEMENT BASED ON SOIL SALINITY LEVEL ON FOUR (4) SUCCESSIVE GREENHOUSE CUCUMBER CROPS. Analele Universitatii din Craiova, seria Biologie, Horticultură, Tehnologia Prelucrării Produselor Agricole, Ingineria Mediului, 2012, XVII (1), pp.195-200. hal-03183527

HAL Id: hal-03183527

https://hal.science/hal-03183527

Submitted on 15 Apr 2021

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>
FERTILIZATION MANAGEMENT BASED ON SOIL SALINITY LEVEL ON FOUR (4) SUCCESSIVE GREENHOUSE CUCUMBER CROPS

Nikolaos Gougoulias, Alexandros Papachatzis, Adamantia Chouliara<fnref n="1" />,

Nikolaos Chouliaras<fnref n="2" />

**Key words:** Soil Electrical conductivity, Soil salinity, Soil Fertility, Greenhouse crop.

ABSTRACT

An assessment of a fertilization management practice for exploitation of soil salts was made in a four successive greenhouse cucumber crops. Only an organic commercial fertilizer in the form of black peat moss slightly enriched with inorganic elements was embedded basically, while during crop, a fertigation program was planned based on soil salinity level. This work confirmed that the plant need for nutrients might be covered largely by soil salts. The basic application of the organic fertilizer in relation to fertigation program applied during of crops period led to a reduced soil electrical conductivity from 0.66 to 0.24, 0.58 to 0.24, 0.80 to 0.49 and 0.55 to 0.39 dS/m respectively (soil extract of 1soil: 5 H₂O). Significant increase in soil salinity was observed after soil solarization, in the first and second crops (EC 1,23 dS/m and EC 0.48 dS/m), however, not observed increase in soil salinity(EC 0.44 dS/m and EC 0.41 dS/m) after soil solarization for the third and the fourth crop. Then, excessive salinity levels in soil should be taken into account when fertilization management of cultural practices in successive crops is applied.

INTRODUCTION

Soil salinity assessment is based on measurement of soil electrical conductivity, a quick, reliable and easy method which could be used during cultivation period for indication of soil fertility in a greenhouse crop (Rhoades *et al*., 1999).

The application of high fertilizer rates in intensive cultures, like greenhouse crops, affects electrical conductivity. In soils from several greenhouses in Thessaly, which have been irrigated with low salinity water, the high electrical conductivity (0.4 dS/m) in soil extracts (soil:H₂O ratio 1:5) is related with the increase concentration of soluble N and K. In these soils the base application of N and K mineral fertilizers in the following culture is

<footnote n="1">¹ Informatics Scientist, data analysis, Technological Educational Institution of Larissa, 41110 Greece</footnote>

<footnote n="2">² Department of Plant Production, Technological Educational Institution of Larissa, 41110 Greece, Corresponding author: E-mail: chouliar@teilar.gr</footnote>
not recommended (Chouliaras *et al.*, 1991). In addition, the concentration of phosphorus in soil is not significantly affected salinity (Chouliaras *et al.*, 1991). The mobility of P in soil is very limited and therefore could remains in soil for many years, in contrast with N and K. Thus, the knowledge of P history fertilizer applications in formers cultures, consists a valuable guide to efficient plant P-nutrition management.

The aim of this work was to develop a fertilization method for a greenhouse cucumber culture, based on soil salinity and fertilizer inputs of the previous crops.

## MATERIALS AND METHODS

Soil samples (to a depth of 15 cm) were taken from a greenhouse located at the Technological Education Institute (TEI) of Larissa, Greece, for physical and chemical soil properties estimation. Soil organic matter, ammonium and nitrate nitrogen, available P and exchangeable K were measured following the Page *et al.* (1982) methods. Organic matter content was calculated by chemical oxidation of soil with 1 mol/l K₂Cr₂O₇ and titration of the remaining reagent with 0.5 mol/l FeSO₄. Soil organic matter was estimated by multiplying soil organic carbon content by the factor 1.724 as reported by Hesse (1972). Both ammonium and nitrate nitrogen were extracted with 0.5 mol/l CaCl₂ and estimated by distillation in the presence of MgO and Devarda's alloy, respectively. Available P (P-Olsen) was extracted with 0.5 mol/l NaHCO₃ and measured by spectroscopy. Finally, exchangeable K was extracted with 1 mol/l CH₃COONH₄ and measured by Flame Photometry (Essex, UK).

According to analysis, the greenhouse soil was loamy sand, slightly calcareous, with alkaline pH, low organic matter content and high Cation exchange capacity (Table 1). The electrical conductivity of soil extracts (water soil extract in ratio1:5) was 0.66 dS/m, indicating marginally increased soil salinity (Chouliaras *et al.*, 1996).

<table><caption>Table 1. Chemical soil properties at the beginning of crops</caption><thead><tr><th>Soil properties</th><th>A<br>Cultivation</th><th>B<br>Cultivation</th><th>C<br>Cultivation</th><th>D<br>Cultivation</th></tr></thead><tbody><tr><td>pH</td><td>8.13</td><td>7,95</td><td>7,50</td><td>7,40</td></tr><tr><td>CaCO<sub>3</sub> (%)</td><td>5.80</td><td>5,60</td><td>5,70</td><td>5,28</td></tr><tr><td>Organic matter (%)</td><td>0.74</td><td>1,47</td><td>2,10</td><td>1,93</td></tr><tr><td>Cation exchange capacity<br>(cmol/kg)</td><td>23,0</td><td>26,5</td><td>27,3</td><td>23,8</td></tr><tr><td>Electrical conductivity<br>in soil extract (1 soil : 5 H<sub>2</sub>O,<br>dS/m)</td><td>0.66</td><td>0,58</td><td>0,80</td><td>0,55</td></tr></tbody></table>

**A. Crop.** Only an organic commercial fertilizer 25 tons/ha (that contains 1,5 kg N, 3,8 kg P₂O₅ and 2,5 kg K₂O per 100 kg fertilizer), in the form of black peat moss slightly enriched with inorganic elements was incorporated in soil before plant transplantation.
Cucumber plants (var. Gador, 10⁴ roots per hectare were used) was transplanting at early April 2008 in greenhouse, and in an area of 100 m². During cultivation period (April-July 2008) plants were watering with good quality water (EC = 0.5 dS/m) while the fertigation programme organized according to plant growth, blooming and fruit load, and soil salinity changes. Forty days after transplanting, leaf samples were taken for plant nutritive elements assessment. As the concentration of N and K in plants was found to be slightly low, fertigation programme modified according to CTIFL guide (1989). Totally, during the whole growing period 110 kg N, 80 kg P (P₂O₅) and 130 kg K (K₂O) per hectare were used for plant fertigation. At the end of growing season, soil covered by transparent polyethylene plastic for soil solarization and the soil electrical conductivity was measured three months later.

**B. Crop:** Later settled the second crop (October-April 2009), following the same procedure, and during the whole growing period 200 kg N, 200 kg P (P₂O₅) and 200 kg K (K₂O) per hectare were used for plant fertigation. At the end of growing season, soil was covered by transparent polyethylene plastic for soil solarization, the soil electrical conductivity was measured three months later, and, the same organic commercial fertilizer with 45 tons/ha was applied.

**C. Crop:** The third cultivation lasted from October-April 2010 and during the whole growing period 80 kg N, 80 kg P (P₂O₅) and 80 kg K (K₂O) per hectare were used for plant fertigation. At the end of growing season, soil was also covered by transparent polyethylene plastic for soil solarization, the soil electrical conductivity was measured three months later, and, the same organic commercial fertilizer of 45 tons/ha was applied.

**D. Crop:** The fourth cultivation lasted from October-April 2011 and during the whole growing period 80 kg N, 80 kg P (P₂O₅) and 80 kg K (K₂O) per hectare were used for plant fertigation. At the end of growing season, soil was equally covered by transparent polyethylene plastic for soil solarization and the soil electrical conductivity was measured three months later.

The experimental design was completely randomized with four replications for each sample analysis. Data was analyzed using Microsoft Excel analysis Tool-Pak.

## RESULTS AND DISCUSSION

The fertigation program decreased soil salinity as indicated by EC reduction from (0.66 to 0.24, 0.58 to 0.24, 0.80 to 0.49 and 0.55 to 0.39 dS/m respectively) during the cultivation period (Fig 1). However, soil solarization after plant removal in the first and second crop increased soil salinity (from 0.24 to 1.23 and 0.24 to 0.48 respectively) due to soluble salts mobility to soil surface caused by intensive evaporation (table 1). After soil solarization the third and the fourth crop the electrical conductivity has remained constant (from 0.49 to 0.44 and 0.39 to 0.40 respectively) which confirms the improvements of the soil salinity.
<figure><img src="image_2.png" /><figcaption>Figure 1. Changes in soil salinity during successive cultivation periods.</figcaption></figure>
Table: 2 shows the balance of available inorganic elements in the soil during growing period. The availability of minerals is due to fertilizer residues from previous crops and nutrients applied via irrigation in the current crop. These data confirm the use of nutritive elements of soil salts from plants. In this case, the salinity level has to be considered for the following crops.

Finally, the fertigation programme did not affect plants yield. The total production of greenhouse cucumber was 6.4 kg/ m² (A-Cultivation), 9.0 kg / m² (B-Cultivation), 9.0 kg/ m² (C-Cultivation) and 9.1 kg / m² (D-Cultivation),

<table><caption>Table 2.
Inorganic elements availability in greenhouse soil</caption><thead><tr><th></th><th>N (kg/ha)<br>Inorganic</th><th>P<sub>2</sub>O<sub>5</sub> (kg/ha)<br>P-Olsen</th><th>K<sub>2</sub>O (kg/ha)<br>Exchangeable</th><th>Electrical<br>conductivity<br>dS/m</th></tr></thead><tbody><tr><td colspan="5"><strong>A - Cultivation</strong></td></tr><tr><td>Soil Content at the<br>Starting of growing<br>season</td><td>490</td><td>70</td><td>1040</td><td>0.64</td></tr><tr><td>Base + Surface<br>fertilizer application</td><td>110</td><td>80</td><td>130</td><td>0.24 (end crop<br>period)</td></tr><tr><td>Soil Content after soil<br>solarization</td><td>730</td><td>80</td><td>1180</td><td>1.23</td></tr><tr><td colspan="5"><strong>B- Cultivation</strong></td></tr><tr><td>Soil Content at the<br>Starting of growing<br>season</td><td>290</td><td>72</td><td>1020</td><td>0.58</td></tr><tr><td>Base + Surface</td><td>215</td><td>238</td><td>223</td><td>0.24(end crop)</td></tr><tr><td>Soil Content after soil<br>solarization</td><td>270</td><td>90</td><td>866</td><td>0.48</td></tr><tr><td colspan="5"><strong>C - Cultivation</strong></td></tr><tr><td>Soil Content at the<br>Starting of growing<br>season</td><td>556</td><td>62</td><td>1070</td><td>0.8</td></tr><tr><td>Base + Surface<br>Fertilizer</td><td>106</td><td>149</td><td>121</td><td>0.49(end crop<br>period)</td></tr><tr><td>Soil Content after soil<br>solarization</td><td>330</td><td>140</td><td>1030</td><td>0.44</td></tr><tr><td colspan="5"><strong>D- Cultivation</strong></td></tr><tr><td>Soil Content at the<br>Starting of growing<br>season</td><td>556</td><td>114.9</td><td>885.8</td><td>0.55</td></tr><tr><td>Base + Surface</td><td>106</td><td>149</td><td>121</td><td>0.39(end crop)</td></tr><tr><td>Soil Content after soil<br>solarization</td><td>265</td><td>115</td><td>873.9</td><td>0.40</td></tr></tbody></table>
CONCLUSION

This study shows that greenhouse soil salinity due to accumulation of fertilizers (residual effect), could be taken into account for basic mineral fertilizer omission. In this way, plant needs for nutrients might partially be covered by soil salts, leading to limited fertilizer application and soil salinity reduction by the end of the growing season. The salinity level in soil should be considered for the management of the cultural practices in successive crops.

In addition, the high content of organic matter in soil reduces the negative effects of salinity (Chouliaras, 1996).

REFERENCES

Chouliaras N. 1990. Organic matter and organic nitrogen in greenhouse soil. Newsletter of Soil Organization, Vol 10-11: 18-20.

Chouliaras N., Mavromatis E., 1991. Nutritional conditions in greenhouses in Thessaly (Greece), Technical Communications of ISHS, International Society for Horticultural Science, Number 287, 221 p.

Chouliaras N., 1996. Greenhouses soil fertility in Thessaly. The Agricultural Association of Larissa, 16: 32-36.

CTIFL, 1989. Memento, Fertilisation des Culture Légumières. Centre Technique Interprofessionnel des Fruits et des Légumes, France, 398p.

Hesse P.R., 1972. A Textbook of Soil Chemical Analysis. John Murray, London.

Page A.L., Miller R.H. and Keeney D.R., 1982. Methods of Soil Analysis Part 2: Chemical and Microbiological Properties. Agronomy, ASA and SSSA, Madison, Wisconsin, USA.

Rhoades J.D., Chanduvi F. and Lesch S., 1999. Soil salinity assessment. Methods and interpretation of electrical conductivity measurements. FAO Irrigation and drainage paper 57.