Значај рационалне технологије гајења озиме пшенице са становишта одрживе пољопривреде

Abstract

На крају XX и почетку XXI века јављају се нови погле- ди односно нове филозофије будућег развоја пољопривреде. Наиме, сматра се да ће развој пољопривреде у новом веку бити заснован на концептима који предвиђају значајне промене у технологији гајења усева и оплемењи- вању биља које би допринеле бољем успостављању еколошке равнотеже и стабилности природних ресурса у агроекосистему (земљиште, вода, клима, природна вегетација). Такви начини гајења биљака поред економске ефек- тивности морали би бити и дугорочно одрживи како би били доступни ге- нерацијама које долазе после нас. Одржива пољопривреда је један од алтер- нативних система земљорадње који је заснован на економској ефикасности и чувању основних природних ресурса (земљишта, воде) и енергије. Технологија гајења озиме пшенице у свету и код нас заснована је на интензивној употреби механизације и агрохемикалија ‒ минералних ђубри- ва и пестицида. Највећи број сорти пшенице је стваран за такве, интензивне услове производње. Интензивну производњу пшенице карактерише велика потрошња енергије и различити ризици који доводе до деградације и за- гађења земљишта и загађења животне средине. Данас је све више различитих праваца у пољопривреди почев од индустријске (конвенционалне) па све до органске пољопривреде. Про- изводно-еколошки услови, односно њихова изражена регионалност, нала- жу непрестано изналажење нових решења у технологији гајења пшенице. Флексибилнија агротехника мора бити спој конвенционалних начина са модерном технологијом која подразумева преиспитивање система обраде земљишта, рационалније ђубрење, интегрални прилаз у заштити биља, пло- дореде са већим учешћем легуминоза, одговарајуће сорте и семенарство. Циљ овог рада је да укаже на значај, нужност и бројне могућности рационализације технологије гајења озиме пшенице у складу са основним постулатима одрживе пољопривреде у Србији.

On the basis of the previous theoretical but also practical knowledge, some things can be listed, which will certainly provoke signifi cant changes in the fi eld of agriculture. First of all, global climatic changes will have their refl ection on the territory of Serbia as well. Th e analysis of the last 20-year weather conditions (temperatures and precipitations) related to winter wheat shows the increase of autumnal and spring temperatures at the end of the fi rst decade of the 21st century. Th e eff ects of a year on winter wheat cannot be avoided. Weather conditions during each production year signifi cantly aff ect plants directly or indirectly through the soil. In recent decades, abiotic extremes caused by climate factors have had stress eff ects on fi led crops. Th e application of cropping practices can provide the undisturbed growth and development of grain crops and can neutralise extreme abiotic climate factors (precipitation, temperature) and their stress eff ects on crops. Th ese adaptations must fi rst and foremost build resilience within agroecosystem, increasing its ability to continue functioning when faced with unexpected events. Under climate conditions in Serbia, winter wheat primarily develops when there is a suffi cient or even surplus amount of precipitation. Th e precipitation surplus adversely aff ects winter wheat. If there is a precipitation defi cit the following indirect measures, which resulted in reduced water requirements by grain crops are employed: balanced NPK nutrition, optimum nitrogen rates, optimum density in accordance with cultivar properties and climate conditions, well developed crop free of disease and pests. Th e choice of a proper cultivar for certain agroecological conditions is increasingly important, because not only dry but also extremely wet years last in a longer period of time. All cultivars have a high potential for yield, but resistance to stress conditions, especially to high temperatures or drought, will be a very important criterion, particularly for more arid regions. In intensive fi eld crop production tillage sistem is of great importance. Tillage system have an eff ect on many physical, chemical and biological properties of soil. Multiple passes of diff erent agricultural machinery have negative eff ect on structure, bulk density, total pore space and compaction as well as increased expencives. Today there is need rational solutions for that problems. Conservation tillage practice can increase the organic matter content, aggregate stability, and improve optimal soil water content, air, temperature, biological regime and nutrient cycling that represent basic elements in erosion control, soil and water conservation and environment protection and preservation. Unfavorable meteorologicaly conditions in dry year, winter wheat low-input technology with conservation soil treatment was more eff ective than conventional. In the year with favorable rainfall, all the advantages were on the other side in treatment with conventional tillage systems. A higher dose of nitrogen in top dressing in winter wheat was more eff ective than a rational dose and in control variant without nitrogen in top dressing. For rational (low-input) technology of winter wheat, the choice of cultivar is particularly important, especially in years with extreme meteorological conditions. Reduction in soil treatment, mineral nutrition and protection was more in line with cultivars for low-iinput, which also aff ected the larger diff erences in the dry season. Rational technology, which includes conventional tillage system and rational amount N had better eff ect in weed control than both of conservation tillage systems had. However, mulch tillage does not lag behind the conventional tillage. Th is is one of possibilities for crop technology rationalization for winter wheat and soil conservation in drought year. No-tillage with no fertilization increased total weednesess and decrease grain yield especially without N fertilization. Th is tillage makes weed control diffi cult. Fertilization with high N level gives better grain yield than the other level. In the year with a more favorable conditions, diff erences in yield between cultivars were less. Low input cultivars of winter wheat especially Evropa, Lasta, and Pobeda positively responded to diff erent technology in winter wheat production by their yield than high-input cultivars (Pesma, Rana niska). Within this group of varieties Europe and Lasta have shown the greatest adaptability which is refl ected in the highest yield of grain. On the conditions created in the technology of cultivation with protective soil treatment, from the varieties for intensive investments, Pesma was reacted very well, unlike the very intense variety Rana niska, which these conditions did not correspond.