Improving Productivity of Citrus Orchards with Rainwater Harvesting and Micro-Irrigation in a Sub-Humid Region

Abstract

Scarcity of water is one of the major factors affecting productivity and decline of citrus orchards. The uneven distribution of rain in space and time induces abundant runoff in tropics. The higher runoff in monsoon period and soil moisture shortage in post monsoon induces sub-optimum yield of citrus orchards. Rainwater harvesting and its efficient utilization in citrus orchards is need of the hour for sustainable citriculture. Keeping this in view, the study was conducted to explore the feasibility of rainwater harvesting and it’s use through drip irrigation in citrus orchards. Various in-situ rainwater conservation treatments viz., continuous trenching, continuous bunding, staggered trenching between the rows across the slope (4.2%) and control (without any soil and water conservation treatment) were evaluated in citrus orchards of central India during 2006-2009. The continuous trenching produced the best response conserving 38% runoff and 32.28% soil besides 15.7% higher fruit yield with better fruit quality. Moreover, rainfall runoff from 3.2 hectare of land with continuous trenches was harvested in a tank of size 35m×35m×3m and recycled with drip irrigation with black plastic mulch in 1ha of Nagpur mandarin. The harvested water also recharged the groundwater in the nearby wells and water from wells was used for irrigation purpose during dry period. Over all, the fruit yield was enhanced up to 110% with better quality fruits under rainwater conservation practices and groundwater use over rain-fed trees. The study suggested for the combine use of rainwater harvesting and drip irrigation with plastic mulch for sustainable production of citrus in the regions having similar agro-climates of the study region.

Nedostatak vode je jedan od najvažnijh faktora koji utiču na smanjenje produktivnosti citrusnih voćnjaka. Nejednak raspored kiše u vremenu i prostoru uzrokuje značajan gubitak vode u tropima. Visok gubitak u periodu monsuna i nedostatak zemljišne vlage posle monsuna smanjuje prinos voćnjaka. Sakupljanje kišnice i njena efikasna upotreba u voćnjacima je hitna potreba održivog uzgoja citrusa. Ova studija je ispitivala izvodljivost skupljanja kišnice i njene upotrebe za navodnjkavanje voćnjaka. Ispitivani su različiti načini čuvanja kišnice u citrusnim voćnjacima centralne Indije u periodu 2006-2009. Neprekidni rovovi dali su najbolji rezultat sa 38% sačuvane kišnice i 32.28% zemlje uz 15.7% veći prinos i kvalitet voća. Pored toga, kišnice sa 3.2 hektara terena sa neprekidnim rovovima sakupljana je u rezervoar dimenzija 35m×35m×3m i korišćena za navodnjavanje kap po kap sa crnim plastičnim malčom na 1ha Nagpur mandarina. Sakupljenom vodom takođe su dopunjavani okolni podzemni izvori, a voda iz ovih izvora je zatim korišćena za navodnjavanje tokom sušnog perioda. Konačno, prinos voća je povećan do 110% uz poboljšanje kvaliteta voća. Ova studija je pokazala da se kombinovana upotreba skupljanja kišnice i navodnjavanja kap po kap, sa plastičnim malčom, može preporučiti za postizanje održive proizvodnje citrusa u regionima koji imaju slične agro-klimatske uslove kao region koji je ispitivan.