WSP02972 - Laserfiche WebLink

Home Browse Search

Although there is room for improvement with the application of known methods, there is much yet to be learned: This promises to be both exciting and ,rel.,arding. In the field of sprinkler irrigation, e.g., we need much more information on the microcl imate surrounding the plants, We know something of the possibil ities of spoon-feeding plant nutrients with 'sprinklers. ~e have had some reports of insect control under' such systems. ' Last summer a sorghum field'was reported completely free of greenbugs af,ter nit'rogenous fertil'izer was applied with the irrigatio'n water: 'Neighboring fields were seriously damaged by the insects. Sprinkle~ irrigation offe~s some'intriguing possibil ities for disease a'nd insect control. , ' ' , . ',I I " , Water requirements 'of plants are in direct proportion' to evapo-, transpiration. Much more must be learned about \-Iay.s 'of reduci'ng this use (or 1055) of \-later. The microclimate men~i6ned earl i~r may be one approach. , Plant breeding may contribute--perhaps varietal differences are significant. Seed and plant treatment with chemicals (such as fatty alcohols) have sho\-ln some promise. Soil surfactants and mulches of various kinds that reduce direct evaporation 'losses may be worthy of, study. Subirrigation, \-Ihich is a revival and updating of the old systems some of us used in our gardens many years ago, may bring some accepta,ble methods. I mentioned ,real istic interpretation of soil tests and, in general, I bel ieve that excessive use of ferti 1 ;zers is' often recommenqed. However, we certainly need more knowledge of the chemical analyses necessary to give us more rei iable information than we can now get. We are told that conventional field crops use only four percent of the sun's energy. Maybe we don't want to use 100 percent of that energy but perhaps there Ls room for improvement. Dreamers have predicted farms under glass and recent expansion in greenhouse tomato production makes one wonder what the future might bring. Certainly we could use more of the sun's energy, more completely control the environment with respect to CO2, humidity, insects, diseases, and plant nutrients as well as irrigation water. 'Perhaps that would be the ultimate 50' far as efficient use of I imited water is concerned. Provision could be made for catching almost every drop of rain that falls and reusing it as much as possible. I have mentioned sprinkler irrigation several times and'may have left the impression that I believe this system of irrigation is as wonder- ful as some of its proponents claim it to be. I have marvelled at the improvements that have been made in sprinkler systems in recent years, They have made possible some sandy land farming that could not otherwise be field crops. I am sure their use will continue. I would suggest one word of caution. Their use on hardland with rather low-qual i ty water presents a serious threat. Al though I am not a soil chemist, it would seem to me that rather frequent, light 14,