Pamuk bitkisinde farklı azot dozlarının ve sulama programlarının kaldırılan N, P miktarlarına etkisi
Küçük Resim Yok
Tarih
1996
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Dünya' da ve özellikle Türkiye' de son yıllarda meydana gelen kuraklık sebebiyle en önemli endüstri bitkilerimizden olan pamuğun yetiştiği alanlarda su sıkıntısı çekilmektedir. Bu nedenlerden optimum ürünü verebilecek kısıtlı sulama yönetimi ile buna bağh olarak azotlu gübre seviyesinin araştırılması zorunlu hale gelmiştir. Bu amaçla; Uluslararası Atom Enerjisi (IAEA) tarafından desteklenen "Pamuk için; yetersiz sulama koşullan altında optimum sulama programlan" adlı bir deneme yürütülmüştür. Desteklenen bu projenin bir dilimini oluşturan bu çalışmada; değişik sulama yönetimleri ve azotlu gübreleme programlarında pamuk bitkisinin farklı organları tarafından topraktan kaldırılan N ve P miktarlan, içerikleri, kurumadde miktarları ve kütlü verimleri araştırılmış ve belirlenmiştir. Bu çalışma, 1994 yılında Ege Üniversitesi Ziraat Fakültesi deneme tarlasında Bölünmüş Parseller Deneme Desenine göre, 4 tekerrürlü, 6 sulama uygulamalı ve 3 azotlu gübre seviyesinde yapılmıştır. Bitki materyali olarak Ege Bölgesinde % 95 ekim alanına sahip Nazilli 84 pamuk çeşidi kullanılmıştır. Azotlu gübreler, 0-60-120 kg ha'1 olacak şekilde Amonyum Sülfat formunda bir defada; fosforlu ve potasyumlu gübrelerin tamamı ise ekimden önce 80 kg ha"1 P203 ve 100 kg ha"1 K20 olacak şekilde Triple Süperfosfat ve Potasyum Sülfat fonnunda banda verilmiştir. Mineral gübrelemeden önce 0-25 cm. derinliğinden toprak örneği alınarak, toprakların bazı fiziksel ve kimyasal özellikleri tesbit edilmiştir. Sulama programları ise vejetatif faz, çiçeklenme fazı ve koza oluşum fazı dönemleri dikkate alınarak; 0-0- 0, T-R (çiftçi sulama uygulaması), 1-0-1, 0-1-1, 1-1-0 ve 1-1-1 sulama yönetimleri şeklinde yapılmıştır. Sulama uygulamalannın yapılabilmesi için 0-30 cm' lik toprak katmanının nem içeriği gravimetrik olarak, 30-90 cm' lik toprak katmanı ise nötronmetre kullanılarak belirlenmiştir. Sulama, kök bölgesi olan 0-90 cm' lik toprak katmanında % 60 faydalı su bulunması dikkate alınarak, farklı dönemlerde stres uygulanan parsellerde ise 0-90 cm' lik toprak katmanında bitkiye faydalı su içeriğinin % 20 düzeyinde seyretmesi göz önüne alınarak sulama yapılmıştır. 72 parseli temsil edecek bitki örnekleri; fizyolojik hasat döneminde hasat edilerek yaprak, gövde, kapsül, lif ve çiğit gibi bitki kısımlarına ayrıldıktan sonra bu organların kurumadde miktarlan ile, N-P içerikleri; modifıye edilmiş kjeldahl ve vanadomolibdofosforik san renk yöntemleriyle tesbit edilmiştir. Araştırmanın bütün farklı konularından tüm yaprağın toplam N (%) içeriğinin 1.719 - 2.311, P içeriğinin (%) ise 0.104 -0.222 arasında değiştiği ve vejetatif46 aksam içinde en çok N - P içeren organın yaprak ayası olduğu belirlenmiştir. Artan azotlu gübre dozuna karşılık yaprak P içeriğinin artmadığı ancak yaprak N içeriğinin arttığı tesbit edilmiştir. Çalışmamızda en yüksek yaprak N içeriği, sürekli su stresi koşullarından (0-0-0), en düşük yaprak N içeriği ise çiftçi sulama uygulamalarından (T-R) ve tam sulama uygulamalarından elde edilmiştir. Yaprak kurumadde içeriği ise 1837 - 4542 kg ha"1 arasında tesbit edilmiş olup bütün bitki organları içerisinde % 28' lik pay ile ilk sırayı almıştır. Sulama ve azotlu gübre dozları arttıkça yaprak kurumadde içeriğinin genelde arttığı başka bir deyişle sulama arttıkça N1 lu gübre isteğinin, N' lu gübreleme arttıkça sulama isteğinin arttığı belirlenmiştir. Yaprak ile kalkan azot içeriklerinin 52.26 -75.46 kg ha"1, fosfor içeriklerinin ise 3.19 - 6.23 kg ha"' arasında değiştiği; yaprakların N ve P içeriklerine zıt olarak tam sulama koşullarında en yüksek, sürekli stres koşullarında ise en düşük olarak bulunmuştur. Çalışmada gövdenin toplam N (%) içeriğinin 0.66 - 1.28, P içeriğinin (%) ise 0.04 -0.10 arasında değiştiği, en yüksek gövde N ve P içeriklerinin sürekli stres koşulları (0-0-0), geleneksel çiftçi uygulamaları (TR) ve çiçeklenme dönemi stres (1-0-1) koşullarından,en düşük oranda ise koza oluşum döneminde strese maaruz bırakılan (1-0-1) ve tam sulamanın yapıldığı parsellerden elde edilmiştir. Artan azotlu gübre dozları pamuk bitkisinin gövde N içeriğini arttırmasına rağmen P içeriğini değişti rmemiştir. Pamuk bitkisinin gövdesi ile 1858 - 2825 kg ha"' arasında değişen miktarlarda kurumadde elde edilerek tüm bitki kısımları içerisindeki payının %21 olduğu belirlenmiştir. Çalışmamızda vejetatif aksam (yaprak ve gövde) ile kalkan N miktarları ortalama olarak 81.82 kg ha"1, P miktarları ise 6.31 kg ha"1 bulunmuştur. Böylece kaldırılan azotun % 39.9' unun, fosforun ise % 28.52' sinin pamuk bitkisinin vejetatif aksamı ile uzaklaştığı belirlenmiştir. Araştırmanın bütün farklı konularından kapsülün minimum ve maksimum N ve P içeriklerinin sırasıyla % 0.88 - 1.49 ve %0.08 - 0.17 arasında değiştiği belirlenmiştir. Sürekli stres koşullarında vejetatif organların N ve P içerikleri en yüksek olarak tesbit edilmesine rağmen generatif organ olan kapsülde en düşük olarak tesbit edilmiştir. Azotlu gübre dozları arttıkça kapsül N içeriğinin arttığı buna karşılık artan azotlu gübre uygulamalarının kapsül P içerikleri üzerine etkili olmadığı ancak sulama uygulamalarının etkili olduğu bulunmuştur. Kapsül kurumadde içeriği ise artan azot dozları ve sulama uygulamalarından ayrı ayrı etkilenmiştir. Pamuk bitkisinin diğer organlarında olduğu gibi en yüksek kurumadde içeriği tam sulama uygulamalarından, en düşük kurumadde içeriği ise bütün dönemlerde strese maaruz bırakılan bitkilerden elde edilmiştir. Çalışmada kapsül kurumaddesinin tüm bitki kurumaddesi içerisindeki payının % 15.2 olduğu belirlenmiştir. Kaldırılan N ve P miktarları ise kapsülün kurumadde miktarının artışı doğrultusunda bir artış göstermiştir. Artan47 dozlarda azotlu gübre uygulamalarının pamuk bitkisinin lif N ve P içeriklerine önemli bir etkisi olmamıştır. Farklı sulama uygulamalarına göre lif azot içerikleri % 0.22 - 0.26, fosfor içerikleri ise % 0.036 - 0.046 gibi çok dar bir değişim aralığı içerisinde varyasyon göstermiştir. Vejetatif organların aksine, sürekli sulama uygulamasından elde edilen pamuk lifinin, bütün dönemlerde strese bırakılan bitkilerin liflerinden daha fazla N ve P içerdiği saptanmıştır. Lif kurumadde miktarı üzerine artan azotlu gübre uygulamalarının etkili olmamasına karşın sulama uygulamaları önemli çıkmıştır. En fazla lif kurumadde içeriği diğer organlarda olduğu gibi tam sulama uygulamalarından, en düşük kurumadde içeriği ise bütün dönemlerde su stresi uygulanan parsellerden elde edilmiştir. Lif kurumadde içeriği bütün bitki kısımları içerisinde ortalama olarak % 15 payla en düşük olmuştur. Lif ile kaldırılan N ve P miktarları ise tamamen lif kurumadde içeriğine göre değişmiştir. Bütün sulama uygulamaları altında lif ile kaldırılan N miktarları 3.69 - 5.77 kg ha"1, fosfor miktarları ise 0.47 - 1.16 kg ha"1 arasında değişim göstermiştir. Farklı sulama ve artan azotlu gübrelemenin ayrı ayrı uygulamalarında çiğit N içeriği % 3.89 - 4.40 arasında, çiğit P içeriği ise % 0.54 - 0.58 arasında değişim göstermiştir. Azotlu gübre dozları arttıkça çiğit P içeriğinin azaldığı bunan karşılık N içeriğinin arttığı görülmüştür. Diğer generatif organlardan farklı olarak bütün dönemlerde sulama uygulanan koşullarda (I -1-1) çiğitin N içeriği sürekli stres uygulanan koşullara göre düşük çıkmasına karşın çiğit ve diğer generatif organların fosfor içerikleri tüm dönem ve çiftçi sulama uygulamalarında yüksek çıkmıştır. Çiğit kurumadde miktarının bütün bitki kısımları içerisindeki miktarı ortalama olarak %23.5 olarak tesbit edilmiş olup artan sulama ile azotlu gübre uygulamalarından ayrı ayrı etkilenmiştir. Çiğit ile kalkan besin madde miktarları 86.35 - 115.11 kg ha"1 N ve 11.70 - 15.44 kg ha"1 P olarak belirlenmiştir. Generatif aksam (kapsül-lif-çiğit) ile kalkan azot miktarları ortalama 125.42 kg ha"1, fosfor miktarları ise 16.27 kg ha"1 olarak bulunmuş ve kaldırılan azotun % 61.16' sının, fosforun ise %73.55' inin pamuk bitkisinin generatif aksamı ile uzaklaştırıldığı tesbit edilmiştir. Artan dozlarda azotlu gübre uygulamalarında, 60 kg ha"1 azot uygulanan parsellerde verimde meydana gelecek olan azalışın, 120 kg ha"1 azot uygulanan parsele göre % 9.7 olduğu belirlenmiş ve 60 kg ha"1 azotun su kısıtlılığı durumlarında verim için yeterli olduğu görülmüştür. Tam sulama muamelesine (1-1-1) oranla, kütlü verimdeki azalma oranları 1-1-0, T-R, 1-0-1, 0-1-1, ve 0-0-0 muamelelerinde sırasıyla % 3.5, % 4.2, % 11.2, % 14.8 ve % 21.9' dur. Bu rakamlardan, koza oluşum safhasında su stresi yaratmanın verimde kaydadeğer düşüşlere sebebiyet vermediği tesbit edilmiştir
The impact of progressive drought on the water resources of irrigation schemes in the western part of Turkey has of vital importance for the last 5 years. Limited availability of irrigation water requires fundamental changes in irrigation management and fertilization. In order to be successful in deficit-partial irrigation, specific growth stages of the major crops at which they can withstand water stress with no effect on plant growth and yield need to be well identified. Thus, it will be possible to develop optimum schedules at optimum fertilization for implementing deficit irrigation programmes. In the Aegean region, cotton is one of the main crops with 250000 ha of planted area. The objective of this study was to improve solutions to the relations between nitrogen fertilization and improved water stress tolerance of cotton. Therefore, nitrogen and phosphorus recoveries (uptakes) of the different parts of cotton were determined and dry weights and seed cotton yields were also assessed at different stress conditions. The experiment was conducted in the experimantal fields of Ege University Bornova, Izmir-Turkey. A local new cotton variety N-84 was used. The soil was clay loam in texture and the water content at field capacity varied from 20.79 to 28.90 % Soil bulk densities were between 1.40 - 1.70 g cm"3 and available water holding capacity for 0.90 m. soil depht was 1 80.5 mm. The soil was neutral in reaction and low in organic matter. CaCOj and C.E.C changed between 10.35 - 13.85 % and 28.25 - 32.08 m.e 100 g"1 respectively. Water soluble salts ranged between 0.059 - 0.085 %. The available P and total N contents were 0.25 ppm and 0. 13 % respectively. The experiment was set up in split plot design with six irrigation treatments as main plots an three nitrogen rates (0 -60 - 120 kg ha'1 ) as subplots, with 4 replications.49 Irrigation Treatments Are Given In The Following In full irrigation the soil water content was allowed to deplete to 60 % of available water content of the plant root zone, whereas in the stress conditions it was depleted to 20-25 % during the specific growth stage, hi the traditional irrigation, water in applied 4 or 5 times with 15 to 25 day intervals during the flowering stage. As for the nitrogen fertilizer rates, 120 kg ha"1 -high input and 60 kg ha"' -low input-were applied. Control plots which dit not receive N fertilizer were present as well. Other fertilizer were dressed for each plot at constant amounts as 80 kg ha"1 P2Os and 100 kg ha"1 K20. Measurements of soil water content and water potantial were taken frequently throughout the growing season. Whole plant soumples were taken from 72 plots at physiological harvest to avoid defoliation. Plants were seperated into leaf, stem, square leaf, lint and seed parts. Dry weights, N and P concentrations were determined by distillation and colorimetric methods respectively. Leaf N and P concentrations (%) were found between 1.719 - 2.311 and 0.104 - 0.222. Among the studied vegetative plant parts, leaf had the highest N and P concentrations. Results showed that increments in N applications increased leaf N but had no significant effect on P concentrations. In this study, highest leaf N concentration was achieved in continuous stress conditions (0-0-0); on the other hand the lowest was measured under T.R application and full irrigation (1-1-1) conditions. Leaf dry weight contents were found to be between 1837 - 4542 kg ha"1 with respect to treatments. In this manner, the leaf had the highest dry weight with 28 %. Data put forth that leaf dry weights generally increased as the irrigation and N fertilizer rates increased. Nitrogen and P uptakes by leaves were found to range between 52.26 - 75.46 and 3. 1950 - 6.23 kg ha"1 respectively. Unlike leaf N and P concentrations, N and P uptakes were found highest in full irrigation an lowest in continuous sress conditions. As for stem nutrient status, N concentration changed between 0.66 - 1.28 % and P between 0.04 -0.10 % where highest amounts were determined in continuous stress (0-0-0), T.R and stress at flowering (1-0-1) and lowest amounts at stress conditions in boll formation (1-0- 1) and full irrigation conditions. In this study, parcels that received more N had higher stem N concentrations however similarity was not found for stem P. Willi respect to treatments, stem dry weights changed from 1858 to 2825 kg ha"1. Among the plant parts the stem shared 21% of the dry weight. Our results showed that 8 1,82 kg ha"1 N was taken up by the vegetative parts (leaf and stem). For P, this amount was found as 6.31 kg ha"1 in average. Therefore 39.9 % of the recovered N and 28.52 % of the P were taken up by the vegetative parts. When all the treatments of this study are considered the minimum and maximum values obtained for boll N and P concentrations were 0.88 - 1.49 % and 0.08 - 0.17 % respectively. Under continuous stress conditions, boll as a generative plant part had the lowest N and P concentrations. Increases in N rates increased boll N contents. However no influence was obtained for P an which irrigation treatments were found effective. Boll dry weights were found to be under the effect of N and irrigation treatments. The highest dry weight was achieved in full irrigation and lowest in continuous sress conditions as had happened in the other parts of cotton. Results showed that boll dry weight shared 15.2 % of the whole plant dry weight. Nitrogen and P uptakes increased parallel with the dry weight increments. Nitrogen rates had no significant effect on lint N and P concentrations. With respect to irrigation treatments, lint N and P concentration had a narrow range between 0.22 - 0.26 % and 0.036 - 0.046 % respectively. Under full irrigation conditions lint had the highest N and P contents. Dry weights were not found under the effect of N fertilization where irrigation was significant. Highest dry weights were obtained in full irrigation conditions and lowest under continuous stress. Lint dry weights had 15 % of the total plant dry weight, m this manner N and P uptakes changed with respect to dry weight increases. Nitrogen and P uptakes of the lint were found to be 3.69 - 5.77 kg ha"1 and 0.47 - 1.16 kg ha"1 respectively. As for seed nitrogen and P concentrations, a change between 3.89 - 4.40 % and 0.54 - 0.58 % was measured. In this case N rates bicreased seed N concentrations. However a similar trend was not determined for P. Unlike other generative plant parts seed concentrations were measured lower in full irrigation conditions; on the other hand, P concentrations were found51 higher. Seed dry weight content shared 23.5 % in whole plant dry weight. N and P uptakes of the seed were found to be 86.35 - 115.1 kg ha"1 and 11.70 -15.44 kg ha"1. If we take into consideration all the generative parts together, 125.42 kg ha"1 for N and 16.27 kg ha'1 for P uptakes are determined. These results put forth that 61. 16 % of N and 73.55 % of P are removed by the generative parts of cotton plants. Low N rate (60 kg ha"1) had a 9.7 % yield decrease when compared to high N rate (120 kg ha"1). However when limitations in water are considered, results showed that 60 kg ha"1 N is sufficient. When the yield of full irrigation (1-1-1) conditions are compared with 1-1-0, T.R, 1-0- 1, 0-1-1 and 0-0-0, a decrease of 3.5 %, 4.2 %, 1 1.2 %, 14.8 %, and 2 1.9 % is seen respectively. It is concluded that irrigation stress in boll formation stage does not create significant yield decreases.
The impact of progressive drought on the water resources of irrigation schemes in the western part of Turkey has of vital importance for the last 5 years. Limited availability of irrigation water requires fundamental changes in irrigation management and fertilization. In order to be successful in deficit-partial irrigation, specific growth stages of the major crops at which they can withstand water stress with no effect on plant growth and yield need to be well identified. Thus, it will be possible to develop optimum schedules at optimum fertilization for implementing deficit irrigation programmes. In the Aegean region, cotton is one of the main crops with 250000 ha of planted area. The objective of this study was to improve solutions to the relations between nitrogen fertilization and improved water stress tolerance of cotton. Therefore, nitrogen and phosphorus recoveries (uptakes) of the different parts of cotton were determined and dry weights and seed cotton yields were also assessed at different stress conditions. The experiment was conducted in the experimantal fields of Ege University Bornova, Izmir-Turkey. A local new cotton variety N-84 was used. The soil was clay loam in texture and the water content at field capacity varied from 20.79 to 28.90 % Soil bulk densities were between 1.40 - 1.70 g cm"3 and available water holding capacity for 0.90 m. soil depht was 1 80.5 mm. The soil was neutral in reaction and low in organic matter. CaCOj and C.E.C changed between 10.35 - 13.85 % and 28.25 - 32.08 m.e 100 g"1 respectively. Water soluble salts ranged between 0.059 - 0.085 %. The available P and total N contents were 0.25 ppm and 0. 13 % respectively. The experiment was set up in split plot design with six irrigation treatments as main plots an three nitrogen rates (0 -60 - 120 kg ha'1 ) as subplots, with 4 replications.49 Irrigation Treatments Are Given In The Following In full irrigation the soil water content was allowed to deplete to 60 % of available water content of the plant root zone, whereas in the stress conditions it was depleted to 20-25 % during the specific growth stage, hi the traditional irrigation, water in applied 4 or 5 times with 15 to 25 day intervals during the flowering stage. As for the nitrogen fertilizer rates, 120 kg ha"1 -high input and 60 kg ha"' -low input-were applied. Control plots which dit not receive N fertilizer were present as well. Other fertilizer were dressed for each plot at constant amounts as 80 kg ha"1 P2Os and 100 kg ha"1 K20. Measurements of soil water content and water potantial were taken frequently throughout the growing season. Whole plant soumples were taken from 72 plots at physiological harvest to avoid defoliation. Plants were seperated into leaf, stem, square leaf, lint and seed parts. Dry weights, N and P concentrations were determined by distillation and colorimetric methods respectively. Leaf N and P concentrations (%) were found between 1.719 - 2.311 and 0.104 - 0.222. Among the studied vegetative plant parts, leaf had the highest N and P concentrations. Results showed that increments in N applications increased leaf N but had no significant effect on P concentrations. In this study, highest leaf N concentration was achieved in continuous stress conditions (0-0-0); on the other hand the lowest was measured under T.R application and full irrigation (1-1-1) conditions. Leaf dry weight contents were found to be between 1837 - 4542 kg ha"1 with respect to treatments. In this manner, the leaf had the highest dry weight with 28 %. Data put forth that leaf dry weights generally increased as the irrigation and N fertilizer rates increased. Nitrogen and P uptakes by leaves were found to range between 52.26 - 75.46 and 3. 1950 - 6.23 kg ha"1 respectively. Unlike leaf N and P concentrations, N and P uptakes were found highest in full irrigation an lowest in continuous sress conditions. As for stem nutrient status, N concentration changed between 0.66 - 1.28 % and P between 0.04 -0.10 % where highest amounts were determined in continuous stress (0-0-0), T.R and stress at flowering (1-0-1) and lowest amounts at stress conditions in boll formation (1-0- 1) and full irrigation conditions. In this study, parcels that received more N had higher stem N concentrations however similarity was not found for stem P. Willi respect to treatments, stem dry weights changed from 1858 to 2825 kg ha"1. Among the plant parts the stem shared 21% of the dry weight. Our results showed that 8 1,82 kg ha"1 N was taken up by the vegetative parts (leaf and stem). For P, this amount was found as 6.31 kg ha"1 in average. Therefore 39.9 % of the recovered N and 28.52 % of the P were taken up by the vegetative parts. When all the treatments of this study are considered the minimum and maximum values obtained for boll N and P concentrations were 0.88 - 1.49 % and 0.08 - 0.17 % respectively. Under continuous stress conditions, boll as a generative plant part had the lowest N and P concentrations. Increases in N rates increased boll N contents. However no influence was obtained for P an which irrigation treatments were found effective. Boll dry weights were found to be under the effect of N and irrigation treatments. The highest dry weight was achieved in full irrigation and lowest in continuous sress conditions as had happened in the other parts of cotton. Results showed that boll dry weight shared 15.2 % of the whole plant dry weight. Nitrogen and P uptakes increased parallel with the dry weight increments. Nitrogen rates had no significant effect on lint N and P concentrations. With respect to irrigation treatments, lint N and P concentration had a narrow range between 0.22 - 0.26 % and 0.036 - 0.046 % respectively. Under full irrigation conditions lint had the highest N and P contents. Dry weights were not found under the effect of N fertilization where irrigation was significant. Highest dry weights were obtained in full irrigation conditions and lowest under continuous stress. Lint dry weights had 15 % of the total plant dry weight, m this manner N and P uptakes changed with respect to dry weight increases. Nitrogen and P uptakes of the lint were found to be 3.69 - 5.77 kg ha"1 and 0.47 - 1.16 kg ha"1 respectively. As for seed nitrogen and P concentrations, a change between 3.89 - 4.40 % and 0.54 - 0.58 % was measured. In this case N rates bicreased seed N concentrations. However a similar trend was not determined for P. Unlike other generative plant parts seed concentrations were measured lower in full irrigation conditions; on the other hand, P concentrations were found51 higher. Seed dry weight content shared 23.5 % in whole plant dry weight. N and P uptakes of the seed were found to be 86.35 - 115.1 kg ha"1 and 11.70 -15.44 kg ha"1. If we take into consideration all the generative parts together, 125.42 kg ha"1 for N and 16.27 kg ha'1 for P uptakes are determined. These results put forth that 61. 16 % of N and 73.55 % of P are removed by the generative parts of cotton plants. Low N rate (60 kg ha"1) had a 9.7 % yield decrease when compared to high N rate (120 kg ha"1). However when limitations in water are considered, results showed that 60 kg ha"1 N is sufficient. When the yield of full irrigation (1-1-1) conditions are compared with 1-1-0, T.R, 1-0- 1, 0-1-1 and 0-0-0, a decrease of 3.5 %, 4.2 %, 1 1.2 %, 14.8 %, and 2 1.9 % is seen respectively. It is concluded that irrigation stress in boll formation stage does not create significant yield decreases.
Açıklama
Anahtar Kelimeler
Ziraat, Agriculture, Azot dozu, Nitrogen dose, Ege bölgesi, Aegean region, Pamuk, Cotton, Sulama programı, Irrigation program, Toprak, Soil
