Determining the Causality Relationship Between Climate Data and Wheat and Barley Yield in Turkey with The Toda-Yamamoto Test

Didem Doğar; Adnan Çiçek

Makale detayları

Determining the Causality Relationship Between Climate Data and Wheat and Barley Yield in Turkey with The Toda-Yamamoto Test

Yazarlar:

Didem Doğar | Adnan Çiçek

Yayıncı:

Tekirdag Namik Kemal University

Ana Başlıklar:

Tarım Ekonomisi (Diğer)

Dergi:

Tekirdağ Ziraat Fakültesi Dergisi Vol.22 Issue 2, pp.411-427

Belge Tipi:

Makale

Yayın Tarihi:

5/2025

Belge Dili:

Türkçe

Document ID (Org No.):

2001348114

pISSN:

1302-7050

Anahtar kelimeler:

Özet:

 The aim of this study is to examine the causality relationship between long-term climate data and wheat and barley yields. The data set of the study covers 53 years of climate data and wheat and barley yields between 1970-2023 in Turkey. Toda-Yamamoto causality test was used to determine the causality relationship between temperature, precipitation, humidity and number of snowy days and wheat and barley yields. For this purpose, firstly Augmented Dickey-Fuller ADF and Phillips-Perron PP unit root tests were performed on the series to determine whether the series contained a unit root in the first difference. Lagrange Multiplier LM Autocorrelation test, White Heteroscedasticity test With Cross and Granger Causality test were applied to determine that there was no autocorrelation or heteroscedasticity problems in the series. According to the Granger Causality test, a causality relationship of 1 was found between wheat yield and temperature, 5 between wheat yield and number of snowy days. A causal relationship of 5 was found between barley yield and temperature and number of snowy days, and 1 between barley yield and humidity values. As a result of the analyses, it was determined that changes in wheat and barley yield were largely dependent on temperature and humidity changes. It was determined that there was a unidirectional causality at a significance level of 1 from temperature, precipitation and number of snowy days to wheat yield. In addition, it was determined that there was a positive relationship between temperature and precipitation and wheat yield, and a negative relationship between number of snowy days and wheat yield. A unidirectional causal relationship at a significance level of 1 was found from temperature, humidity and number of snowy days to barley yield. It was determined that there was a positive relationship between temperature and barley yield, and a negative relationship between humidity and number of snowy days and barley yield. In the light of these findings, it is seen that climate variables have a significant effect on wheat and barley yield. In addition, it is important to analyze the effects of climatic factors such as temperature, humidity, precipitation and number of snowy days on agricultural production, and to take the necessary precautions for future food security and sustainable agriculture.

 The aim of this study is to examine the causality relationship between long-term climate data and wheat and barley yields. The data set of the study covers 53 years of climate data and wheat and barley yields between 1970-2023 in Turkey. Toda-Yamamoto causality test was used to determine the causality relationship between temperature, precipitation, humidity and number of snowy days and wheat and barley yields. For this purpose, firstly Augmented Dickey-Fuller ADF and Phillips-Perron PP unit root tests were performed on the series to determine whether the series contained a unit root in the first difference. Lagrange Multiplier LM Autocorrelation test, White Heteroscedasticity test With Cross and Granger Causality test were applied to determine that there was no autocorrelation or heteroscedasticity problems in the series. According to the Granger Causality test, a causality relationship of 1 was found between wheat yield and temperature, 5 between wheat yield and number of snowy days. A causal relationship of 5 was found between barley yield and temperature and number of snowy days, and 1 between barley yield and humidity values. As a result of the analyses, it was determined that changes in wheat and barley yield were largely dependent on temperature and humidity changes. It was determined that there was a unidirectional causality at a significance level of 1 from temperature, precipitation and number of snowy days to wheat yield. In addition, it was determined that there was a positive relationship between temperature and precipitation and wheat yield, and a negative relationship between number of snowy days and wheat yield. A unidirectional causal relationship at a significance level of 1 was found from temperature, humidity and number of snowy days to barley yield. It was determined that there was a positive relationship between temperature and barley yield, and a negative relationship between humidity and number of snowy days and barley yield. In the light of these findings, it is seen that climate variables have a significant effect on wheat and barley yield. In addition, it is important to analyze the effects of climatic factors such as temperature, humidity, precipitation and number of snowy days on agricultural production, and to take the necessary precautions for future food security and sustainable agriculture.

 The aim of this study is to examine the causality relationship between long-term climate data and wheat and barley yields. The data set of the study covers 53 years of climate data and wheat and barley yields between 1970-2023 in Turkey. Toda-Yamamoto causality test was used to determine the causality relationship between temperature, precipitation, humidity and number of snowy days and wheat and barley yields. For this purpose, firstly Augmented Dickey-Fuller ADF and Phillips-Perron PP unit root tests were performed on the series to determine whether the series contained a unit root in the first difference. Lagrange Multiplier LM Autocorrelation test, White Heteroscedasticity test With Cross and Granger Causality test were applied to determine that there was no autocorrelation or heteroscedasticity problems in the series. According to the Granger Causality test, a causality relationship of 1 was found between wheat yield and temperature, 5 between wheat yield and number of snowy days. A causal relationship of 5 was found between barley yield and temperature and number of snowy days, and 1 between barley yield and humidity values. As a result of the analyses, it was determined that changes in wheat and barley yield were largely dependent on temperature and humidity changes. It was determined that there was a unidirectional causality at a significance level of 1 from temperature, precipitation and number of snowy days to wheat yield. In addition, it was determined that there was a positive relationship between temperature and precipitation and wheat yield, and a negative relationship between number of snowy days and wheat yield. A unidirectional causal relationship at a significance level of 1 was found from temperature, humidity and number of snowy days to barley yield. It was determined that there was a positive relationship between temperature and barley yield, and a negative relationship between humidity and number of snowy days and barley yield. In the light of these findings, it is seen that climate variables have a significant effect on wheat and barley yield. In addition, it is important to analyze the effects of climatic factors such as temperature, humidity, precipitation and number of snowy days on agricultural production, and to take the necessary precautions for future food security and sustainable agriculture.

 Bu çalışmanın amacı, uzun dönemli iklim verileri ile buğday ve arpa verimi arasındaki nedensellik ilişkisini incelemektir. Çalışmanın veri seti, Türkiyede 1970-2023 yılları arasındaki 53 yıllık iklim verileri ile buğday ve arpa verimlerini kapsamaktadır. Sıcaklık, yağış, nem ve karlı gün sayısı ile buğday ve arpa verimi arasındaki nedensellik ilişkisinin belirlenmesinde Toda-Yamamoto nedensellik testinden yararlanılmıştır. Bu amaçla ilk olarak serilerin Augmented Dickey-Fuller ADF ile Phillips-Perron PP birim kök testi yapılmış, serilerin birinci farkında birim kök içerip içermediği belirlenmiştir. Lagrange Çarpanı LM Otokorelasyon Testi, White Değişen Varyans Testi With Cross ve Granger Nedensellik testi uygulanmış, serilerde otokorelasyon ve değişen varyans sorunu bulunmadığı tespit edilmiştir. Granger nedensellik testine göre, buğday verimi ile sıcaklık arasında 1, buğday verimi ile karlı gün sayısı arasında 5 düzeyde nedensellik ilişkisi bulunmuştur. Arpa verimi ile sıcaklık ve karlı gün sayısı arasında 5, arpa verimi ile nem değerleri arasında 1 düzeyde nedensellik ilişkisi bulunmuştur. Yapılan analizler sonucunda, buğday ve arpa verimindeki değişimlerin büyük oranda sıcaklık ve nem değişikliklerine bağlı olduğu belirlenmiştir. Sıcaklık, yağış ve karlı gün sayısından buğday verimine doğru 1 anlamlılık düzeyinde tek yönlü nedensellik olduğu belirlenmiştir. Ayrıca, sıcaklık ve yağış ile buğday verimi arasında pozitif, karlı gün sayısı ile buğday verimi arasında negatif bir ilişki olduğu belirlenmiştir. Sıcaklık, nem ve karlı gün sayısından arpa verimine doğru 1 anlamlılık düzeyinde tek yönlü nedensellik ilişkisi saptanmıştır. Sıcaklık ve arpa verimi arasında pozitif, nem ve karlı gün sayısı ile arpa verimi arasında negatif bir ilişki olduğu belirlenmiştir. Bu bulgular ışığında, iklim değişkenlerinin buğday ve arpa veriminde önemli bir etkiye sahip olduğu görülmektedir. Ayrıca, sıcaklık, nem, yağış ve karlı gün sayısı gibi iklim faktörlerinin tarımsal üretim üzerindeki etkilerinin analiz edilmesi, gelecekteki gıda güvenliği ve sürdürülebilir tarım için gerekli önlemlerin alınması önem taşımaktadır.

Makale detayları

Determining the Causality Relationship Between Climate Data and Wheat and Barley Yield in Turkey with The Toda-Yamamoto Test

Yazarlar:

Didem Doğar | Adnan Çiçek

Yayıncı:

Tekirdag Namik Kemal University

Ana Başlıklar:

Tarım Ekonomisi (Diğer)

Dergi:

Tekirdağ Ziraat Fakültesi Dergisi Vol.22 Issue 2, pp.411-427

Belge Tipi:

Makale

Yayın Tarihi:

5/2025

Belge Dili:

Türkçe

Document ID (Org No.):

2001348114

pISSN:

1302-7050

Toda-Yamamoto test

Wheat and barley yield

Climate change

Causality analysis

TurkeyToda-Yamamoto testi

Buğday ve arpa verimi

İklim değişikliği

Nedensellik analizi

Türkiye

Sayı

Makale detayları

Yazarlar: Didem Doğar | Adnan Çiçek

Yayıncı: Tekirdag Namik Kemal University

Ana Başlıklar: Tarım Ekonomisi (Diğer)

Dergi: Tekirdağ Ziraat Fakültesi Dergisi Vol.22 Issue 2, pp.411-427

Belge Tipi: Makale

Yayın Tarihi: 5/2025

Belge Dili: Türkçe

Document ID (Org No.): 2001348114

pISSN: 1302-7050

Sayı

Yazarlar:

Didem Doğar | Adnan Çiçek

Yayıncı:

Tekirdag Namik Kemal University

Ana Başlıklar:

Tarım Ekonomisi (Diğer)

Dergi:

Tekirdağ Ziraat Fakültesi Dergisi Vol.22 Issue 2, pp.411-427

Belge Tipi:

Makale

Yayın Tarihi:

5/2025

Belge Dili:

Türkçe

Document ID (Org No.):

2001348114

pISSN:

1302-7050