CLIMATE CHANGE AND PRECIPITATION NEEDS OF WINTER WHEAT Éva Erdélyi, Corvinus University of Budapest Levente Horváth, University of Debrecen

though the variability of the temperature doesn’t change much for the used climate scenarios, the estimated maize production does. SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY Climate determines agricultural production. Climate change in Hungary is characterized by increases in temperature and less precipitation → decreased yield? geographical analogues: future climate in Hungary is similar to the present climate of South-Southeast Europe. Horváth (2006, later today) the risk of wheat production in Hungary between 1950 and 1990 has been increased, partly independently to the risk aversion of the decision maker. Ladányi (2006) (Debrecen region: the increase is quite high and even quicker.) we analyzed the biomass changes of maize and saw that moderate warming can increase the yield, but more increase of the temperature can cause big losses (by using 4M model for different climate scenarios as weather inputs). And:

Scenarios Climate scenarios can be defined as pictures of how the climate may look like in the future. Our work is based on GCMs downscaled to Debrecen. For comparison we used: Scenario BASE with the parameters of our days, Scenarios created by Geophysical Fluid Dynamics Laboratory (USA) GFDL2535 and GFDL5564 (finer resolution), with consideration of CO2 increase in atmosphere, and three very different scenarios worked out by United Kingdom Meteorological Office (UKMO): UKHI (high-resolution equilibrium climate change exp.), UKLO (low-resolution equilibrium climate change exp.) and UKTR (high-resolution transient climate change experiment). SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY j This time we wanted to see the effects of climate change through analyzing the precipitation needs of winter wheat. Center of agricultural production and our research: Debrecen

SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY Growing season of winter wheat

November: the grains need to be in wet soil, so it’s very important to have precipitation for and after sowing (especially in the observed region, because of the continental climate). too much - unable to sow → restricted production area, lower yield less than enough - the plant is too week for winter. SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY May: precipitation good for big grain mass, but if too much, - stormy, beatens down the crop → unsuitable for harvesting, - more fungal deseases → lower yield, big variability in production (quality and quantity) Precipitation is a great limiting factor in some periods of growing:

Results for november and may: Precipitation amount almost the same (a bit less), BUT all scenarios show big variability. For the entire growing season: precipitation amount won’t change. Can we say the same for the whole course of development? SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY July: precipitation not good, because of harvesting, but:

SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY the answer is NO, for example for July rising temperatures increase the crops’ water demand, the precipitation is even harmful in some stages of growing, too wet soil and high evapotranspiration produce lower yield, winter wheats yield grows with less precipitation in some periods of growing (the observed sums of the precipitations for the growing season show a slow decrease and the scenarios predict smaller values in the future - this might be good), we see a big variability in the amounts of the precipitation → the frequency and the probability of extreme weather events such as droughts and floods increases? precipitation, less information conditions in different phenological stages? Problems, questions

From sowing to emergence mm of precipitation was measured in the past. Climate scenarios (except UKHI) predict the same amounts for the future: SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY

Winter wheat is very sensitive on meteorological circumstances in the stem elongation – spikelet initiation period. In this period precipitation is of higher importance than temperature: the shortage of precipitation can be seen, for example in leaf development, too wet soil and high evapotranspiration produce lower yield. In this phase the plant was having mm of precipitation in the past and the forecasted values are not very good for any of the climate scenarios we used.

SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY The variability is very high. high variability → extrem events → high risk unpredictible future → preventive adaptation strategies are needed In case of drough the crop response is halving the yield. Our response can be watering for increasing the production.

For the anthesis-grain filling phenological phase, - when the plant develops its generative organs mm of precipitation was measured in the past. Florets may not develop with lower amounts, which leads to smaller yield. We can be satisfied with the forecasted values of the climate scenarios: SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY

We calculated the R95, the percent of days in a given year, when the daily precipitation amount on a wet day is out of the 95th percentile calculated for the period We used KKT program (Szenteleki, 2006) which also gives as the precipitation amount on wet days in the period, using the same climate scenarios. Normally this index is around 5 percent, but we can see many differences. This means that the precipitation has significant variability. This result (and some other calculated indeces) can give us information for predicting extreme conditions, too. Too few and too much precipitation are both very unfavourable for winter wheat growing, and the unpredictibility (because the high variability we see in the frequency and in the amount of the precipitation in almost all phenological stages for all of the used climate scenarios) even more.

R95, mmmin1min2averagemax2max1 BASE UKHI UKLO UKTR GF GF SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY R95, daysmin1min2averagemax2max1 BASE UKHI UKLO UKTR GF GF Means: distribution asimetric to positive direction. Values as small as bigger the flatness of the distribution.

SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY Analyzing the future winter wheat production, the effects of the climate change, sensitivity (lethal limits, …) of the plant to different climate conditions, especially extrem weather events using the hungarian crop model 4M and other models as SIRIUS (plant growing model) and STICS (plant production model) and the same climate scenarios, Further plans: to analyze the influences of the climate change on other crops production, too. Plans

SUMMER UNIVERSITY ON IT IN AGRICULTURE AND RURAL DEVELOPMENT – 2006 DEBRECEN, HUNGARY Thank you!