cultivar_22_Final_EN

16 ANALYSIS AND PROSPECTIVE STUDIES CULTIVAR Issue 22 APRIL 2021 improved plant varieties that raise productivity but require more artificial agroecosystems than tradi- tional varieties. This intensification based on indus- trial inputs achieved the desired rise in productivity of cultivated land but at the cost of an increasingly inefficient use of these inputs, leading to their exces- sive loss. This in turn(1) expanded the emissions of polluting nitrates, phosphates, greenhouse gases and persistent pesticides; and (2) accelerated the exhaustion of useful natural resources, such as water, soil, biodiversity, energy and multiple ecosys- tem services. Today, we are thus faced with the intensification dilemma. On the one hand, the decline in cultivated land due to soil degradation and urban develop- ment, the unacceptable environmental price of expanding cultivated land at the cost of the remain- ing natural ecosystems and the need to raise agricul- tural production – in response to demographic growth, changing diets in developing countries and demand for agricultural raw materials for non-food purposes such as biofuels – requires higher production per hectare of cultivated land, i.e. greater intensification. On the other hand, past intensifica- tion, based on higher industrial inputs per hectare of cultivated land, is no longer possible and/or desira- ble due to the clear limits we now face. First, the environmental footprint from intensification based on inputs – both in terms of chemical pollu- tion and the loss of planetary biodiversity – must be reduced. Second, the past method to genetically improve plants seems to be facing serious limits with regard to the desired increase in plant response to fertilisers and pesticides in order to raise land productivity, cut costs and control pollution. These limits relate to the path followed in the past to raise productivity: con- centrating most of the product of a cultivated plant’s photosynthesis into a grain by using plants with lots of grain and little stem, and not so much to raise the photosynthetic production of the agroecosystem as a whole. It so happens that plants need roots, stalks and leaves and cannot consist merely of the ear and grain. Therefore, the powerful path to plant improve- ment followed until now is losing steam before an alternative of equal short- and medium-term poten- tial has appeared (Brown, 2004). Third, water depletion today affects numerous stretches of farmland, particularly in the most popu- lated regions on the planet, such as China and India (Brown, 2004). Fourth, the expected impacts of climate change on crop yields and water resources, above all in areas where those yields are already low, such as sub-Sa- haran Africa and the Mediterranean basin, challenge our global agricultural capacity in the future. Fifth, dependence on cheap fossil fuels, prompted by the input-based intensification model, has made farm pro- duction highly vulnerable to energy prices, which is par- ticularly relevant in the cur- rent structural environment of rising energy prices. Therefore, overcoming the intensification dilemma implies producing more per hectare of cultivated land without needing to raise inputs per hectare, which requires a change in the technological model used in farming. So, first we will look at several char- acteristics of the current technological model – the chemical-mechanical model – on which intensifica- tion has been based. This will enable us to identify the outline of the required transition towards a new model: sustainable intensification. However, overcoming the intensification dilemma requires more than a change in the technological model. It requires changing the behaviour of food producers, consumers and science and technology producers, which takes us into the realm of public policy. The need for new policies requires in turn that we act nor just like consumers, producers or Therefore, overcoming the intensification dilemma implies producing more per hectare of cultivated land without needing to raise inputs per hectare, which requires a change in the technological model used in farming.