Abstract: The invention relates to a mineral wool plant substrate comprising a coherent matrix of mineral wool and up to 20 volume % of an ion-exchange agent comprising a variable and/or fixed ion-exchange capacity of about 15, preferably 30 and most preferably 40 meq/100 g dry weight or more.

Abstract: The invention provides a method of growing plants (2) in a growth substrate comprising supplying water to the growth substrate into a first conduit (4) directly connected at one end (3) to the growth substrate and through the first conduit into a second conduit (5) connected to the other end of the first conduit characterised in that the second conduit is at least partially filled with air and the water is released from the first conduit into air space in the second conduit and in that the growth substrate is formed of organic polymeric foam. The invention also provides an apparatus for carrying out the method.

Abstract: A method of monitoring one or more growing plants comprising: (i) providing at least one plant in a growth substrate which contains water, (ii) providing a monitoring system comprising (a) a first data storage means containing stored data on the optimum water oxygen levels for at least one, preferably at least two, sets of growth conditions and (b) a first calculating means for comparing input actual growth conditions and actual water oxygen levels with the stored data and producing a first output result and (c) input means for supplying to the monitoring system actual growth conditions and actual water oxygen levels, the process comprising: (iii) measuring the actual water oxygen level in the region around the roots of the at least one plant, (iv) providing the actual water oxygen level to the first calculating means, (v) determining at least one growth condition and supplying the growth condition to the first calculating means, whereby (vi) the first calculating means compares the actual water oxygen level

Abstract: The invention provides a method of growing plants comprising supplying water to the plants so that the plant roots contact a body of water and drawing water through a suction device (3) provided in contact with the body of water and into a first conduit (4) connected at one end to the suction device (3) and through the first conduit (4) into a second conduit (5) connected to the other end of the first conduit (4), characterised in that the second conduit (5) is at least partially filled with air and the water is released from the first conduit (4) into air space in the second conduit (5). The invention also provides an apparatus suitable for carrying out the method.

Abstract: A method of monitoring one or more growing plants comprising: (i) providing at least one plant in a growth substrate which contains water, (ii) providing a monitoring system comprising (a) a first data storage means containing stored data on the optimum water oxygen levels for at least one, preferably at least two, sets of growth conditions and (b) a first calculating means for comparing input actual growth conditions and actual water oxygen levels with the stored data and producing a first output result and (c) input means for supplying to the monitoring system actual growth conditions and actual water oxygen levels, the process comprising: (iii) measuring the actual water oxygen level in the region around the roots of the at least one plant, (iv) providing the actual water oxygen level to the first calculating means, (v) determining at least one growth condition and supplying the growth condition to the first calculating means, whereby (vi) the first calculating means compares the actual water oxygen level