FINAL REPORT
Period Covered by the Report: / The Project has been going on since the contract was signed on 31 July 1998.Project Title: / SOLVING THE PROBLEM OF WATER SURPLUS / DEFICIENCY ON ARABLE AREAS OF FAMILY FARMS
Contract Number: / 525-02-98-33 of 31 July 1998
Date of Project Commencement: / 01 October 1998
Principal Investigator: / Prof. Franjo Tomić, Ph.D.
Participating Institution: / Faculty of Agriculture, University of Zagreb
Department of Soil Amelioration
In Zagreb, on 30 October 2001
Prof. Franjo Tomić, Ph.D.
(Principal Investigator)
FINAL REPORT
Research Theme
The research theme was ”Solving the problem of water surplus/deficiency on arable areas of family farms”. The research aim was to solve the problem of controlling water deficiency (by irrigation) as well as the problem of surplus water (by drainage) at family farms. The main goal of irrigation is maintenance of optimal soil moisture during the growing period. Maintaining optimal soil moisture requires adequate water dosage in irrigation practice. Water dosing involves two major elements:irrigation rate and the moment when irrigation should be started.
Irrigation rate is the quantity of water added with one application of irrigation (mm or m 3/ha) and it should be calculated before starting irrigation.
The moment of irrigation start is the time when irrigation should be started and it is one of the most important elements of the application of irrigation. In practice, the moment of irrigation start is determined in several ways. One of the methods is the estimation of everyday evapotranspiration, which is based on the input and output of water in the growing period (water balance). The bioclimatic method involves determination of the irrigation coefficient, which represents the ratio of total water consumed per 1 degree of mean daily air temperature (mm/oC). The ratio is commonly determined per decades.
The three-year results of investigating bioclimatic coefficients are given in the enclosed table.
The trials were conducted at the family farm of Zlatko Hlapčić in Međimurje.
An apple plantation was irrigated using dripping irrigation and mini sprinklers. Trials were also carried out at the family farm of Zlatko Orsag, also in Međimurje. Irrigation trials were done on sugar beet and on potato. A watermelon irrigation trial was set up at the family farm of Danko Romić in the Neretva river valley.
Research results were presented at the 36th Meeting of Croatian Agronomists, Opatija, 2000. The abstract was included in the Book of Abstracts.
The paper entitled “Determining the irrigation start by bioclimatic coefficients” was written by a group of authors: F.Tomić, I. Šimunić, D. Petošić, D. Romić, I. Stričević.
Application of drainage measures can solve the problem of surplus water. Surplus water is a serious problem in plant production in the Sava valley. Surplus water aggravates, or even prevents, normal cultivation of agricultural crops on a number of family farms. For this reason, we have conducted field and laboratory research at the family farm of Fran Petranović in the Siće village near Nova Kapela in Slavonia and suggested a solution, with concrete measures of detailed drainage and their standards. This problem was also addressed in the papers authored by F.Tomić, D. Petošić, I. Šimunić, I. Stričević; and D. Petošić, F.Tomić, I. Stričević, B. Rus, which were presented at the Meeting of Croatian Agronomists, Opatija, 1999 and 2000. The abstracts were included in the Book of Abstracts.
Technology
Based on this research, farmers can determine the moment of irrigation start in a practical and fairly precise way. Namely, the procedure of applying the moment of irrigation start by irrigation coefficients is very simple. One should have a thermometer and record air temperatures at 7, 14 and 21 hours (or be in touch with the nearest meteorological station to obtain the mean daily air temperature values). The mean daily air temperature should be calculated from the said values. The mean daily air temperature is then multiplied by the coefficient (of the appertaining decade). In this way, water consumption per 1 degree of the mean daily air temperature (mm water/oC) is calculated for one day. Water consumption (everyday evapotranspiration) per days is added up until the value of the previously estimated irrigation rate is reached. At the moment when the sum of several-days evapotranspiration equals an irrigation rate, irrigation should start.
Farmers in the Sava valley can apply the measures of detailed drainage to solve the problem of surplus water on hydromorphic soils (as it was done in this research at the family farm Petranović in the Siće village). These solutions are described in the Semi-annual Report of 12 April 2001.
Economic Analysis (Profitability)
The current cost of the irrigation system (drip irrigation, mini sprinklers, sprinkling irrigation with Typhon) amounts to 30,000 – 45,000 Kn/ha. Correct irrigation (expert water dosage), however, results in reliable and high crop yields. Thus, for instance, 60,000 – 70,000 kg/ha of apples can be achieved. In contrast, apple yields of about 40,000 kg/h are obtained in case of inexpert dosing of water (estimating the moment of irrigation start by experience). Thus, the application of irrigation coefficients (as in this research) results in a 30-40% higher yield of apples.
Also, if adequate irrigation measures are applied (as it was done at Mr. Petranović’s farm), efficient production of agricultural crops can be attained. Unless detailed drainage is applied on hydromorphic soils in the Sava valley, agricultural production is unreliable or fully unfeasible.
Applicability
Applicability of the research results (calculated irrigation coefficients) is 100%, but for the tested crops (apple, sugar beet, potato and watermelon) and for the regions in which irrigation coefficients were estimated (Međimurje and the Neretva valley).
Applicability of certain detailed drainage measures at the Petranović family farm is also 100%, but for hydromorphic soils (amphigley and hypogley) in the Sava valley. To get reliable solutions of detailed drainage for other soils and other regions, field and laboratory hydropedological investigations have to be done.
Evaluation of farmers
At family farms (apple plantation of Mr Zlatko Hlapčić and watermelons of Mr Danko Romić), the calculated irrigation coefficients are applied to set the moment of irrigation start. Prompted by the large interest, we gave lectures to the farmers and the employees of the Agricultural Extension Institute in Čakovec and Opuzen. This led to a further increase of interest in the application of this method of setting the moment of irrigation start, not only for apples and watermelons but also for other crops that require irrigation.
The proposed measures of detailed drainage for controlling surplus water were also applied at the family farm Petranović in the Siće village.
Quantitative data
The enclosed table presents the average values of irrigation coefficients obtained for the tested crops in the three research years.
Irrigation coefficients(mm/oC) for apple, sugar beet and potato in Međimurje, and for watermelon in the Neretva valley.
Month / Decade / Apple / Sugar beet / Potato / WatermelonMay / 1 / 0.16 / 0.10 / 0.11 / -
2 / 0.17 / 0.12 / 0.13 / 0.15
3 / 0.17 / 0.12 / 0.14 / 0.15
June / 1 / 0.18 / 0.13 / 0.16 / 0.22
2 / 0.21 / 0.15 / 0.19 / 0.33
3 / 0.27 / 0.16 / 0.19 / 0.40
July / 1 / 0.34 / 0.19 / 0.20 / 0.40
2 / 0.34 / 0.23 / 0.21 / -
3 / 0.37 / 0.20 / 0.19 / -
August / 1 / 0.40 / 0.16 / 0.17 / -
2 / 0.35 / 0.15 / 0.15 / -
3 / 0.25 / 0.15 / 0.17 / -
Average / 0.27 / 0.15 / 0.17 / 0.28
Research has pointed to the need of installing drainage pipes on hydromorphic soils in the Sava valley at 15 and 20 m spacing (amphigley) and 25 m (hypogley). Amphigley soil also requires gravel in the drainage ditch as well as subsoiling and liming, as supplementary agricultural management practices.
Qualitative data
Production of apples and other crops on permeable sandy soils in Međimurje is very questionable and risky. Under irrigation, however, safe and high production of good quality fruits is achieved. Irrigation is a particularly useful measure in dry years, like the last two years: But, also other adverse weather events can do considerable harm. This primarily applies to frost and hail, which occurred this year (in the wider area of Croatia) and caused quantitatively and qualitatively much lower yields (particularly of fruit crops).
It is noteworthy that there is precipitation deficiency in the Neretva valley during spring and summer months, so it is almost impossible to grow watermelons without irrigation whereas stable and high watermelon yields are achieved under irrigation.
Conclusions
Determination of the moment of irrigation start by means of irrigation coefficients is a simple and reliable procedure and hence we recommend its application for all crops that require irrigation.
To achieve stable agricultural production with satisfactory yields on hydromorphic soils, application of detailed drainage systems is recommended. Concrete choice of drainage measures and their standards requires field and laboratory hydropedoloical research to be done for each location.