GIS Modeling of Site-Specific Fertilization Requirements

Application of Geographic Informatic System (GIS) in land-planning management has been well known among researchers for over 40 years, and for site-specific fertilization, it started to be recognized in the early 90s. GIS modeling in agriculture helps to identify site-specific distribution of a certain characteristics, and by creating theme maps associated with a database, a visual display of numerical information for a certain field site can be created. Present study of GIS modeling of sustainable crop selection and optimization of fertilization used the database from AGRI-CONTO-CLEEN project and decision making support systems (DSS) based on agronomists expertise. The aim of our study was to determine and visually display soil properties, needs for liming and fertilization recommendations on two family farms (Vinogradci and Berak). The soils of two investigated farms differ significantly in soil properties as well as in needs for nutrient application. GIS modeling identified liming requirement only on Vinogradci site. The same site was characterized by more intensive fertilization requirement, indicating lower soil quality and lower suitability for agricultural production at Vinogradci site. Proposed fertilizing recommendations considered application of farm yard manure to decrees the application of mineral fertilizers and cost of fertilizers and to improve the soil quality, particularly on the Vinogradci farm. GIS modeling in sustainable crop selection and optimization of fertilization contribute to easier, faster and accurate decisions within agricultural production and helps to reduce negative impact on the environment

SOIL MOISTURE REGIME ON LUVISOL IN THE EAST CROATIA

Cilj je istraživanja bio utvrditi manjak vode u tlu tijekom vegetacijskoga razdoblja kukuruza i pšenice na osnovi poljskih mjerenja i proračuna bilance oborinske vode u tlu do dubine 60 cm. Manjak vode u tlu u prvoj godini istraživanja (2003.) bio je izražen tijekom cijele vegetacije kukuruza (Zelčin 336,1 mm, Donji Miholjac 325,7 mm), a najveći je manjak evidentiran u srpnju i kolovozu, što se negativno odrazilo na prosječni prinos od 5,52 t ha-1. Druga godina istraživanja (2004.) bila je znatno povoljnija te je manjak vode u tlu tijekom vegetacije pšenice zabilježen samo u svibnju na oba lokaliteta (Zelčin 40,5 mm, Donji Miholjac 32,6 mm), što nije bitnije utjecalo na prinos zrna pšenice (5,08 t ha-1). Izrazito niske vrijednosti trenutačne fiziološki aktivne vlage tla (FAv) zabilježene su tijekom ljeta 2003. godine, a najniže vrijednosti (Zelčin 8% FAv-a, Donji Miholjac 7% FAv-a) izmjerene su u trećoj dekadi rujna, dok su više vrijednosti utvrđene 2004. godine, uz minimume 38% FAv-a u Zelčinu i 33% 8% FAv-a u Donjem Miholjcu. Statistički značajno više vrijednosti trenutačne vlage tla (P<1%) utvrđene su u dubljim slojevima tla na oba lokaliteta. Utvrđene su i statistički vrlo značajne korelacije (r=0,93**, r=0,91**) između mjerenja i proračunatih vrijednosti FAv-a na oba lokaliteta.The aim of the research was to determine water deficit in the soil (to 60 cm depth) on the basis of field measurements as well as calculation of soil water balance during the vegetation season of maize and winter wheat. In the first year of research (2003) water deficit was emphasized during the whole vegetation season of maize (Zelčin 336 mm; Donji Miholjac 326 mm); but the most marked water shortage was evident in the July and August; having negative effect on maize grain yield (5.52 t ha-1). The second year of research (2004) was more favourable; and water deficit which on the both sites occurred only in the May (Zelčin 40;5 mm; Donji Miholjac 32;6 mm); did not affect wheat grain yield (5.07 t ha-1). Particularly low values of available water content (AWC) were observed during the summer of 2003; and the lowest values (8% for Zelčin; and 7% for Donji Miholjac) were recorded in the third decade of September. In the 2004 much higher values of AWC were achieved (40.5% for Zelčin; and 32.6% for Donji Miholjac). In the deeper soil layers significantly higher (P<1%) values of soil moisture were determined. The correlations between measured and calculated values of AWC were also very significant on both sites (r =0.93**; r =0.91**)

Influence of physical and chemical properties of different soil types on optimal soil moisture for tillage

Plastičnost je tla područje konzistencije tla, odnosno predstavlja promjenu stanja tla zbog različite vlažnosti tla djelovanjem vanjskih sila. Konzistencija određuje veličinu otpora koje tlo pruža pri obradi, stoga je cilj istraživanja utvrditi optimalno stanje vlažnosti tla za obradu te utjecaj fizikalnih i kemijskih svojstva oraničnih horizonata na plastičnost tla, kao jednog od svojstava konzistencije. Istraživanje je provedeno na tri različita tipa tla: aluvijalnome, lesiviranome te na ritskoj crnici. Utvrđene su statistički značajne razlike između svih istraživanih tipova tala i to za sadržaj čestica gline, gustoću pakiranja, aktualnu i supstitucijsku kiselost, kationski izmjenjivački kapacitet tla te sadržaj kalcija. Također, utvrđene su statistički značajne razlike između istraživanih tipova tala za donju granicu plastičnosti, gornju granicu plastičnosti te indeks plastičnosti. Prosječna utvrđena vrijednost donje granice plastičnosti, kao važnog elementa za određivanje optimalnoga trenutka obrade tla, iznosila je 18,9% mas. na aluvijalnome tlu, 24,0% mas. na lesiviranome tlu, dok je na ritskoj crnici iznosila 28,6% mas. Vrlo značajnu korelaciju pozitivnoga smjera s granicama plastičnosti pokazali su humus, glina, KIK, sitni prah, magnezij, natrij i kalcij, dok su vrlo značajnu korelaciju, ali negativnoga smjera, pokazali hidrolitička kiselost, krupni pijesak, sitni pijesak i krupni prah. Kreiranim regresijskim modelima može se procijeniti optimalno stanje vlažnosti tla za obradu na temelju osnovnih svojstava tala. Preciznost modela značajno se povećava uvođenjem većega broja fizikalnih i kemijskih svojstva tla, a dopunsku preciznost modela mogu povećati podatci o tipu tla.Soil plasticity is the area of soil consistency, i.e. it represents a change in soil condition due to different soil moisture influenced by external forces activity. Consistency determines soil resistance in tillage, therefore, the aim of the research was to determine the optimum soil moisture condition for tillage and the influence of the chemical and physical properties of the arable land horizons on the soil plasticity on three different types of soil (fluvisol, luvisol and humic glaysol). Statistically significant differences were found between all examined soil types, such as the content of clay particles, the density of packaging and the actual and substitution acidity, the cation exchange capacity and the content of calcium. There were also statistically significant differences between the examined types of soil for the plasticity limit, liquid limit and the plasticity index. The average established value of plasticity limit as an important element for determining the optimal moment of soil tillage was 18.9% mass on fluvisol, 24.0% mass on luvisol and 28.6% mass on humic glaysol. Very significant positive direction correlation with plasticity limits was shown by organic matter, clay, fine silt, magnesium, sodium and calcium, while very significant negative direction correlation was shown by hydrolytic acidity, coarse sand, fine sand and coarse silt. Created regression models can estimate the optimal soil moisture condition for soil cultivation based on the basic soil properties. The model precision is significantly increased by introducing a greater number of agrochemical and agrophysical soil properties, and the additional precision of the model can be increased by soil type data

Influence of physical and chemical properties of different soil types on optimal soil moisture for tillage

Plastičnost je tla područje konzistencije tla, odnosno predstavlja promjenu stanja tla zbog različite vlažnosti tla djelovanjem vanjskih sila. Konzistencija određuje veličinu otpora koje tlo pruža pri obradi, stoga je cilj istraživanja utvrditi optimalno stanje vlažnosti tla za obradu te utjecaj fizikalnih i kemijskih svojstva oraničnih horizonata na plastičnost tla, kao jednog od svojstava konzistencije. Istraživanje je provedeno na tri različita tipa tla: aluvijalnome, lesiviranome te na ritskoj crnici. Utvrđene su statistički značajne razlike između svih istraživanih tipova tala i to za sadržaj čestica gline, gustoću pakiranja, aktualnu i supstitucijsku kiselost, kationski izmjenjivački kapacitet tla te sadržaj kalcija. Također, utvrđene su statistički značajne razlike između istraživanih tipova tala za donju granicu plastičnosti, gornju granicu plastičnosti te indeks plastičnosti. Prosječna utvrđena vrijednost donje granice plastičnosti, kao važnog elementa za određivanje optimalnoga trenutka obrade tla, iznosila je 18,9% mas. na aluvijalnome tlu, 24,0% mas. na lesiviranome tlu, dok je na ritskoj crnici iznosila 28,6% mas. Vrlo značajnu korelaciju pozitivnoga smjera s granicama plastičnosti pokazali su humus, glina, KIK, sitni prah, magnezij, natrij i kalcij, dok su vrlo značajnu korelaciju, ali negativnoga smjera, pokazali hidrolitička kiselost, krupni pijesak, sitni pijesak i krupni prah. Kreiranim regresijskim modelima može se procijeniti optimalno stanje vlažnosti tla za obradu na temelju osnovnih svojstava tala. Preciznost modela značajno se povećava uvođenjem većega broja fizikalnih i kemijskih svojstva tla, a dopunsku preciznost modela mogu povećati podatci o tipu tla.Soil plasticity is the area of soil consistency, i.e. it represents a change in soil condition due to different soil moisture influenced by external forces activity. Consistency determines soil resistance in tillage, therefore, the aim of the research was to determine the optimum soil moisture condition for tillage and the influence of the chemical and physical properties of the arable land horizons on the soil plasticity on three different types of soil (fluvisol, luvisol and humic glaysol). Statistically significant differences were found between all examined soil types, such as the content of clay particles, the density of packaging and the actual and substitution acidity, the cation exchange capacity and the content of calcium. There were also statistically significant differences between the examined types of soil for the plasticity limit, liquid limit and the plasticity index. The average established value of plasticity limit as an important element for determining the optimal moment of soil tillage was 18.9% mass on fluvisol, 24.0% mass on luvisol and 28.6% mass on humic glaysol. Very significant positive direction correlation with plasticity limits was shown by organic matter, clay, fine silt, magnesium, sodium and calcium, while very significant negative direction correlation was shown by hydrolytic acidity, coarse sand, fine sand and coarse silt. Created regression models can estimate the optimal soil moisture condition for soil cultivation based on the basic soil properties. The model precision is significantly increased by introducing a greater number of agrochemical and agrophysical soil properties, and the additional precision of the model can be increased by soil type data

Influence of physical and chemical properties of different soil types on optimal soil moisture for tillage

Soil plasticity is the area of soil consistency, i.e. it represents a change in soil condition due to different soil moisture influenced by external forces activity. Consistency determines soil resistance in tillage, therefore, the aim of the research was to determine the optimum soil moisture condition for tillage and the influence of the chemical and physical properties of the arable land horizons on the soil plasticity on three different types of soil (fluvisol, luvisol and humic glaysol). Statistically significant differences were found between all examined soil types, such as the content of clay particles, the density of packaging and the actual and substitution acidity, the cation exchange capacity and the content of calcium. There were also statistically significant differences between the examined types of soil for the plasticity limit, liquid limit and the plasticity index. The average established value of plasticity limit as an important element for determining the optimal moment of soil tillage was 18.9% mass on fluvisol, 24.0% mass on luvisol and 28.6% mass on humic glaysol. Very significant positive direction correlation with plasticity limits was shown by organic matter, clay, fine silt, magnesium, sodium and calcium, while very significant negative direction correlation was shown by hydrolytic acidity, coarse sand, fine sand and coarse silt. Created regression models can estimate the optimal soil moisture condition for soil cultivation based on the basic soil properties. The model precision is significantly increased by introducing a greater number of agrochemical and agrophysical soil properties, and the additional precision of the model can be increased by soil type data