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WonderIndigenous ecology fact

Amazonian dark earth, or terra preta, is an unusually fertile black soil made by people. Over generations, charcoal, broken pottery, bones and food waste built up around Indigenous settlements and turned thin rainforest soil rich.

MIT / Amazonian dark earth research

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The story behind the card

Terra preta is Portuguese for 'black earth'. These soils formed between about 450 BCE and 950 CE at sites across the Amazon Basin, and in places the dark layer reaches one to two metres deep. Ordinary rainforest soil is poor, because heavy rain washes nutrients away, but charcoal barely breaks down and holds nutrients and water in place for centuries. Local farmers still use the soil today. It also changed how archaeologists see the Amazon: not as untouched wilderness, but as a landscape shaped by large, settled communities. Scientists now try to copy the method with 'biochar', charcoal made from farm waste and mixed into poor soils.

Türkçe oku
Amazon kara toprağı ya da terra preta, insan eliyle oluşmuş, alışılmadık derecede verimli, kapkara bir topraktır. Yerli yerleşimlerinin çevresinde kuşaklar boyunca biriken odun kömürü, çanak çömlek kırıkları, kemikler ve yemek artıkları, yağmur ormanının yoksul toprağını zenginleştirdi.

Terra preta, Portekizcede “kara toprak” demektir. Bu topraklar yaklaşık MÖ 450 ile MS 950 arasında Amazon Havzası'nın pek çok yerinde oluştu; koyu katman yer yer bir iki metre derinliğe iner. Yağmur ormanının sıradan toprağı yoksuldur, çünkü şiddetli yağmurlar besinleri yıkayıp götürür. Odun kömürü ise neredeyse hiç çözünmez; besini ve suyu yüzyıllarca toprakta tutar. Yöredeki çiftçiler bu toprağı bugün de kullanıyor. Terra preta, arkeologların Amazon'a bakışını da değiştirdi: Burası el değmemiş bir vahşi doğa değil, kalabalık ve yerleşik toplulukların biçimlendirdiği bir yerdi. Bilim insanları bugün aynı yöntemi, tarım atıklarından yapılıp yoksul topraklara karıştırılan “biyokömür”le taklit etmeye çalışıyor.

Sources and further reading

Background reading: Terra preta
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