---
title: "John D. Hamaker"
chunk: 5/5
source: "https://en.wikipedia.org/wiki/John_D._Hamaker"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:06:25.991451+00:00"
instance: "kb-cron"
---

== Rocks for Crops ==
In 2007, the research organization Rocks for Crops was initiated by soil scientist, Jairo Restrepo Rivera of the University of Pelotas, Rio Grande do Sul (Brazil), who translated Bread From Stones into Spanish and gave conferences on remineralization in Colombia, Brazil and Mexico; Peter Von Straaten from the University of Guelph (Canada); and Suzi Teodoro from the University of Brasília (Brazil).
The group confirmed that a branch of geology called agrogeology, originating at the University of Guelph, was evolving, since Von Straaten published the book Agrogeology: The Use of Rocks for Crops and Rivera produced the book and video, Manual Práctico ABC de la Agricultura Orgánica y Harina de Rocas, which described how to regenerate overcultivated soils with rock dust. The science was developing in Germany, Canada and USA, and being researched in Brazil, Tanzania and the Canary Islands. Other university researchers included professors William Fyfe and Ward Chesworth.
The science of agrogeology is the study of natural geological materials suitable for restoring soils as an alternative to chemical fertilizers, particularly for worn out tropical soils. Due to intense tropical rainfall, chemical fertilizers are washed away from laterite soils within weeks, and cannot be stored by the soils, are thus especially harmful to the groundwater. Rock fertilizers supply nutrients over longer periods to cultivated plants. When the rocks break down, new minerals are made available to the soil micro-organisms and whole soil-food web. From the soil chemist's perspective, the process improves the ion-exchange capacity of soils while forming new clay minerals.
In November 2009, a Rocks for Crops conference was held in Brasília with 170 participants to discuss the new science. Further conferences were held in Rio de Janeiro and in Mexico, in December 2009 for the study and promotion of remineralization worldwide.

== Legacy ==
Hamaker conducted the groundwork for a mass movement of people concerned about the health of the world's soils, sustainable forests, climate change and improved nutrition from food. His proposal, rock dusting, known to enhance plant growth by nourishing biological and chemical aspects of the rhizosphere, resulted in soil regeneration to boost global plant cover. This assisted Earth's self-regulation and offered a more natural geoengineering solution to the climate crisis not dependent on high technology, or on-going climate manipulation by man. Some scientists have postulated that technological solutions may exist to assist the remineralization process, such as converting carbon dioxide into organic carbon to be mineralized as sediment before being weathered to soil.

== Writings ==
Hamaker's main book was The Survival Of Civilization (1983, 2002). He also produced various articles and publications from the 1960s to the 1990s. His ideas were further elucidated by Donald A. Weaver in his book To Love & Regenerate The Earth (2002), and in articles for publications including Living Nutrition magazine, resulting in the publication of the e-book "Regenerate the Earth!: Nature's Call to Remineralize Our Soil, Re-Green Our Land, Rescue Our Climate and Restore Our Health" by Vibrance!, in 2001. Weaver remains involved in education campaigns to alert humanity to the climate crisis and foundational rock dust solution.

== Criticisms ==

=== Energy ===
Hamaker's hypothesis is criticised because fossil fuel energy is potentially required to create and distribute rock dust, and this generates CO2 when derived from fossil fuel, however, rock dust is predominantly a byproduct of the existing aggregate and quarrying industries  Future rock dust production for broad-scale soil remineralization can be powered by renewable sources, such as wind energy and bio-fuels grown on remineralized soils.

=== Climate control ===
Since land is naturally fertilized in glacial periods, remineralizing the Earth would emulate the glaciation process, allowing the reversal of what Hamaker and Weaver referred to as the interglacial soil demineralization and retrogressive vegetational succession (decline in the vegetative index). They reasoned that this would indefinitely sustain the interglacial ecosystem and climate, or at least slow down the speed of re-glaciation. However, scientists such as Mukul Sharmar, Charles A. Perry, Yuk Yung, Nigel Calder, Henrik Svensmark, Eigil Friis-Christensen, Knud Lassen and Alexander Chizhevsky who have cited variations in the sunspot cycle as the dominant mechanism in climate cycles on Earth, not vegetation, have yet to incorporate the demineralization dimension.
More than a mini ice age in 2013–2041, Hamaker's immediate concern was the shortening of the growing season from the coming glacial period, which he believed could be forestalled through rock dusting, resulting in more abundant yields at harvest. He believed the coming glacial period would preceded by an interglacial-to-glacial transition phase already underway since the 1970s, and strongly advocated an intensive global co-operative soil remineralization effort to maintain the quantity of food while improving its quality. To achieve this, he recommended simultaneous remineralization of dying forests and soils, also needed to grow bio-fuels, as part of a goal to return excessive carbon dioxide to stable interglacial levels of 280 ppm.

== See also ==
Immobilization (soil science)
Mineralization (soil)
Noctilucent clouds
Remineralisation
Rockdust
Rock flour

== References ==

== External links ==
Renew The Earth