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کد خبر : 191759

تاثیرات نامطلوبی که مصرف بی‌رویه کودهای شیمیایی بر آب و خاک می‌گذارند

تاثیرات نامطلوبی که مصرف بی‌رویه کودهای شیمیایی بر آب و خاک می‌گذارند

ایسنا/چهارمحال و بختیاری عضو هیات علمی گروه باغبانی دانشگاه شهرکرد گفت: اگر مصرف کودهای شیمیایی زیاد شود سبب شوری خاک شده که این مسئله خود به تدریج سبب اثرات منفی مانند کاهش عملکرد گیاه، جذب‌نشدن برخی از عناصر مانند پتاسیم و مشکل در جذب آب می‌شود و گیاه با صرف انرژی بیشتر، آب مورد نیاز خود

تاثیرات نامطلوبی که مصرف بی‌رویه کودهای شیمیایی بر آب و خاک می‌گذارند

ایسنا/چهارمحال و بختیاری عضو هیات علمی گروه باغبانی دانشگاه شهرکرد گفت: اگر مصرف کودهای شیمیایی زیاد شود سبب شوری خاک شده که این مسئله خود به تدریج سبب اثرات منفی مانند کاهش عملکرد گیاه، جذب‌نشدن برخی از عناصر مانند پتاسیم و مشکل در جذب آب می‌شود و گیاه با صرف انرژی بیشتر، آب مورد نیاز خود را جذب می‌کند، به‌علاوه کودها می‌توانند به آب‌های زیرزمینی نفوذ پیدا کرده و بر سلامتی انسان، اثر بدی بگذارد.

رحیم برزگر در گفت‌وگو با ایسنا با بیان اینکه کودها به چند دسته تقسیم‌بندی می‌شوند، اظهار کرد: از نظر نوع عناصری که در کودها وجود دارد ممکن است کودها، نیتروژن‌دار، فسفردار، آهن‌دار، پتاسیمی، منیزیمی، گوگردی و کلسیمی باشند.

عضو هیات علمی گروه باغبانی دانشگاه شهرکرد با اشاره به اینکه کودها ممکن است اسیدزا، قلیازا یا خنثی باشند، افزود: برخی از کودها ممکن است خالص باشند و برخی دیگر دارای ناخالصی زیادی هستند.

این مدرس دانشگاه در خصوص استفاده از چه نوع کود برای زمین کشاورزی یا گلخانه توضیح داد: این مسئله بستگی به نوع خاک، نوع محصول و نوع کشت داشته، برخی از کودها را می‌توان برای زمین استفاده کرد اما حق استفاده از آن‌ها در گلخانه وجود ندارد، چرا که در گلخانه میزان برداشت محصول زیاد است و اگر محصول برداشتی، خوراکی باشد در این نوع کشت‌ها باید از کود با خلوص بالا و عناصر سنگین کم و قابل حل در آب استفاده کرد.

عضو هیات علمی گروه باغبانی دانشگاه شهرکرد ادامه داد: برای زمین کشاورزی که کشت آن خاکی است، می‌توان از کودهایی با ناخالصی بیشتر استفاده کرد، چرا که در زمین‌های کشاورزی کودها با خاک‌پاش در زمین پخش می‌شوند، این کودها در داخل آب آبیاری حل شده و سپس استفاده می‌شوند و اگر در آب حل نشوند ممکن است باعث گرفتگی قطره‌چکان‌ها شود.

برزگر تاکید کرد: بستگی به اینکه کشت در گلخانه از نوع خاکی یا هیدروپونیکی باشد، نوع کود مصرفی مشخص می‌شود، به‌طوری که در کشت‌های هیدروپونیکی از انواعی از کودهای شیمیایی استفاده می‌شود که دارای خلوص بالا بوده و حلالیت بالایی داشته باشند چون به‌مرور در خاک آزاد شده و جذب گیاه می‌شوند.

این مدرس دانشگاه بیان کرد: اگر کشت در زمین کشاورزی باشد، می‌توان از کودهایی استفاده کرد که حلالیت پایینی دارند، چرا که به مرور زمان، عناصر  در داخل خاک  آزاد شده و جذب گیاه می‌شوند، بسته به نوع خاک منطقه و در مناطقی مانند شهرکرد یا مناطق مرکزی ایران که خاک دارای PH قلیایی بوده و یا آهک زیادی دارد از کودهای اسیدزا مانند نیترات آمونیوم، اوره، سولفات آمونیوم و سوپر فسفات تریپل استفاده می‌شود.

عضو هیات علمی گروه باغبانی دانشگاه شهرکرد با اشاره به اینکه نمی‌توان در زمین‌های آهک‌دار از کود فسفات معمولی استفاده کرد، یادآور شد: چرا که در داخل این نوع کودها مقداری گچ وجود دارد و می‌تواند سبب افزایشPH  خاک شود، برعکس در زمین‌های شمال کشور که خاک‌ها اسیدی هستند، باید از کودهای قلیایی مانند نیترات کلسیم استفاده کرد.

برزگر درخصوص ضرر کودهای شیمیایی تصریح کرد: هرچقدر ناخالصی کود بالاتر باشد، مضرات آن بیشتر است، عناصری مانند سرب، کادمیوم، نیکل در کود شیمیایی وجود داشته و می‌توانند جذب گیاه شوند و مضر هستند.

این مدرس دانشگاه اضافه کرد: اگر مصرف کودهای شیمیایی زیاد شود سبب شوری خاک شده که این مسئله خود به تدریج سبب اثرات منفی مانند کاهش عملکرد گیاه، جذب‌نشدن برخی از عناصر مانند پتاسیم و مشکل در جذب آب می‌شود و گیاه با صرف انرژی بیشتر، آب مورد نیاز خود را جذب می‌کند، به‌علاوه کودها می‌توانند به آب‌های زیرزمینی نفوذ پیدا کرده و بر سلامتی انسان، اثر بدی بگذارد.

وی با بیان اینکه کودهای شیمیایی می‌توانند باعث از بین بردن ساختمان خاک شوند، افزود: به‌علاوه خاکدانه‌ها را از بین برده، تهویه خاک را کاهش داده و ظرفیت نگهداری عناصر غذایی را در خاک کم می‌کنند.

عضو هیات علمی گروه باغبانی دانشگاه شهرکرد با اشاره به اینکه میزان مصرف کود شیمیایی در گلخانه و زمین قواعد خود را دارد، افزود: اینکه چه گیاهی قرار است کشت شود، چه عناصری در طول دوره رشد از داخل خاک گرفته شود تا گیاه بتواند رشد خود را کامل کند، در میزان مصرف کود موثر هستند.

وی اضافه کرد: در مرحله بعد باید دید در داخل خاک چه میزان عناصر غذایی وجود داشته و گیاه چه میزان عناصر غذایی نیاز دارد، آن‌گاه باید تفاوت این دو مقدار را مشخص کرد و اگر به اندازه نیاز کود مصرف شود مشکلی پیش نمی‌آید.

برزگر در پایان درخصوص کودهای گیاهی خاطرنشان کرد: این نوع کودها به‌دلیل بهبود میزان ماده آلی خاک، افزایش ظرفیت نگهداری عناصر غذایی خاک و نیز اسیدی کردن خاک می‌تواند کمک زیادی در رشد گیاه داشته باشند و کودهای گیاهی در مقایسه با کودهای شیمیایی، معایبی مانند عناصر سنگین و شوری خاک را به دنبال ندارند.

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