Evaluation of the irrigation water treatment technology (MAXGROW) on its effects on the yield of vegetable crops

Dr. Athanasios Gertsis

Department of Environmental Systems Management, Precision Agriculture Laboratory, Perrotis College,

American Farm School, Thessaloniki, Greece, e-mail: agerts@afs.edu.gr

 

Executive Summary of Greenhouse Study – 2015

During the last two decades, irrigation water quality has become worst in terms of increasing its salinity and causes severe problems in many cultivated crop species, resulting in lower yield. In addition, the scarcity of irrigation water due to overuse is another limitation for increasing food and feed production. This study evaluates a water treatment technology (MAXGROW) for its potential to minimize effects of saline irrigation water and its possible effects of crop productivity. A greenhouse study in pots was undertaken using two substrates (a sandy loam soil and a mixture of pumice and a composted material in 4:1 v/v ratiol), four vegetable species (green onions, spinach, radishes and arugula) irrigated with two qualities of irrigation water (a highly saline with EC~8 dS/m and a regular irrigation water with EC~0,6 dS/m) treated and untreated with the MAXGROW technology. The results (comprehensive Table 1) showed an increased yield caused by the treated saline water in almost all species and the two substrates. The potential of this device was shown to be very promising. Additional studies in greenhouse are in progress currently for continuous evaluation using more plant species, growth substrates and soil types and higher salinity level irrigation water.

 

Table 1. Yield results for each substrate,  irrigation type and plant species

SUBSTRATE	Irrigation type	Crop species	Fresh Yield (g/pot)	Statistical significance*
Pumice+Compost	Saline water-Treated	Arugola	195,4	ab
Pumice+Compost	Regular water-Treated	Arugola	203,6	a
Pumice+Compost	Saline water-Non treated	Arugola	180,2	ab
Pumice+Compost	Regular water-Non treated	Arugola	171,8	b
Sandy loam soil	Saline water-Treated	Arugola	176,2	a
Sandy loam soil	Regular water-Treated	Arugola	135,4	b
Sandy loam soil	Saline water-Non treated	Arugola	124,6	bc
Sandy loam soil	Regular water-Non treated	Arugola	106	c
Pumice+Compost	Saline water-Treated	Green onions	106,8	ab
Pumice+Compost	Regular water-Treated	Green onions	81,8	b
Pumice+Compost	Saline water-Non treated	Green onions	115,2	a
Pumice+Compost	Regular water-Non treated	Green onions	92,6	ab
Sandy loam soil	Saline water-Treated	Green onions	142,8	a
Sandy loam soil	Regular water-Treated	Green onions	97,4	b
Sandy loam soil	Saline water-Non treated	Green onions	101,4	b
Sandy loam soil	Regular water-Non treated	Green onions	142,8	a
Pumice+Compost	Saline water-Treated	Radish	70,6	b
Pumice+Compost	Regular water-Treated	Radish	82,2	ab
Pumice+Compost	Saline water-Non treated	Radish	106,6	a
Pumice+Compost	Regular water-Non treated	Radish	89,4	ab
Sandy loam soil	Saline water-Treated	Radish	129,6	a
Sandy loam soil	Regular water-Treated	Radish	70	b
Sandy loam soil	Saline water-Non treated	Radish	34,8	c
Sandy loam soil	Regular water-Non treated	Radish	63,4	b
Pumice+Compost	Saline water-Treated	Spinach	77,4	ab
Pumice+Compost	Regular water-Treated	Spinach	57,2	b
Pumice+Compost	Saline water-Non treated	Spinach	100,6	a
Pumice+Compost	Regular water-Non treated	Spinach	63,6	b
Sandy loam soil	Saline water-Treated	Spinach	129,2	a
Sandy loam soil	Regular water-Treated	Spinach	112,4	a
Sandy loam soil	Saline water-Non treated	Spinach	130,4	a
Sandy loam soil	Regular water-Non treated	Spinach	110,2	a

 

* Treatments not connected by same letter are significant different

 

The saline water (mixed sea water and irrigation water to bring the EC to ~ 8dS/m) treated with the MAXGROW device increased statistically the yield in many cases while in all cases caused the very high yield. Then only crop species that was not affected by irrigation type was spinach in the sandy loam soil. In the sandy loam soil substrate, the saline water treated produced the highest yields in all four crop species (spinach, radish, green onions and arugula), while in the Pumice+Compost substrate the yield was among the top in all crop species but not as high and significant as in the sandy loam substrate.