Study On The Production Characters Of Alfalfa Under Different Fertilizer Level

The　alfalfa　is　the　high-quality　perennial　legume　family　herb　,　and　at　the　same　time　it　is　a　kind　of　fine　improving　the　soil　and　fostering　and　apply　fertilizer　plant,　it　has　extensive　adaptability　in　the　semi-arid　region　of　the　aridity.　But　the　planting　of　the　alfalfa　still　remains　at　traditional　stage　at　present,　plant　the　lean　unfertile　land　,　saline　and　alkaline　on　the　ground　that　is　not　irrigating　the　condition　mainly,　does　not　apply　fertilizer　basically　or　seldom　apply　fertilizer,　management　is　extensive,　it　is　not　high　in　output　to　cause　alfalfas,　the　variety　degradates,　quality　is　reduced,　fail　to　give　full　play　to　as　the　enormous　productive　potentialities　of　the　forage　grass.　Through　observation　of　the　law　grows　and　study　to　the　alfalfa　under　different　competence　of　applying　fertilizer,　This　text　analyses　different　biological　properties,　production　structure,　difference　moisture　of　utilization　efficiency　,　production　structure　of　department　on　the　ground　and　under　ground　in　different　fertilizer　level　in　alfalfa.　Utilize　the　mathematics　model　to　study　fertilizer　N　,　P　,　K　impact　on　yield　of　the　alfalfa,　set　up　the　optimum　scheme　of　applying　fertilizer　for　high　yield　of　alfalfa,　use　the　N,P,K　rationally　for　the　arid　and　semi-arid　areas　alfalfa,　improve　the　output　of　alfalfas　and　benefit　to　offer　scientific　basis,　in　order　to　promote　arid　and　semi-arid　areas　development　of　regional　economy,　develops　the　grass　industry　of　alfalfas　and　offers　the　culture　theoretical　foundation　.　The　results　as　follow:　1.　The　botany　properties　of　the　alfalfa　exists　obvious　difference　in　different　fertilizer　level.　In　the　first　harvest,　F4　,　F10　,　F14　,　F22　,　F19　,　F13　,　F20　,　F9　the　plant　are　tall,　the　stem　stalk　are　stalwart,　the　single　stem　are　heavy,　they　have　long　among　festival,　many　blades　and　strong　the　ability　of　the　branch　and　have　properties　of　better　production.　In　the　recycled　grass,　it　is　better　botany　properties　of　F16　,　F12　,　F10　,　F4　,　F14　,　F22　,　F23.　Because　of　the　influence　of　applying　fertilizer,　the　important　factor　(single　stem　is　heavy　,　the　single　branch　is　counted　)　resulting　in　forming　biological　output　differs　greatly　under　different　competence　of　applying　fertilizer,　it　the　first　heavest　,　recycled　grass　have　differs　in　different　fertilizer　level　to　the　same　alfalfa　variety,　and　it　is　the　main　reason　that　lead　to　a　difference　in　the　total　amount　of　the　hay　.　2.　The　economic　properties　of　the　alfalfa　exists　obvious　difference　in　different　fertilizer　level.　Looking　from　different　harvest,　the　first　harvest　account　for　61.56%　of　total　amount　hay,has　the　biggest　contribute　to　the　output　of　the　hay　of　the　whole　year.　Recycled　grass　output　of　the　hay　has　the　greater　contribution　rate　to　the　whole　year　too,　it　takes　38.43%　of　the　output　of　the　hay　of　the　whole　year.　the　recycled　grass　is　a　steady　key　to　obtain　the　high　yield　of　alfalfa.　F6　,　F9　have　the　fast　grow　speed　in　first　harvest,　but　recycled　property　is　weak　,　which　influence　the　total　amount　hay　of　the　whole　year.　F23　,　F15　,　F4　,　F19　,　F21　,　F10　grow　characteristic　is　obvious,　grow　ability　is　strong　,　the　total　amount　hay　of　the　whole　year　is　higher　than　that　of　other　fertilizer　level.　　　3.　The　root　system　characteristic　of　the　alfalfa　exists　obvious　difference　in　different　fertilizer　level.　The　diameter　of　main　root　and　main　root　dry　weight　are　ranged　from　0.83　to　1.57cm　,　there　are　obvious　different　in　different　fertilizer　level.　Main　root　of　F4　,　F11　,　F12　,　F5　,　F9　,　F1　are　thick　and　heavy　,　side　roots　are　many　,　the　lateral　root　is　thick　in　diameter　,　the　root　system　is　heavy　in　total　amount.　It　indicates　that　these　fertilizer　levels　can　promote　the　growth　of　the　alfalfa　root　system.　Looking　from　root　neck　characteristic　of　different　treatment,　F4　,　F13　,　F12　,　F11　root　neck　are　thick　in　diameter,　the　root　neck　is　bury　deeply,　root　neck　branches　are　many,　the　diameter　of　the　root　neck　branch　is　not　big　in　different　fertilizer　treatment.　4.　The　vertical　production　structure　of　the　alfalfa　on　the　ground　exists　obvious　difference　in　different　fertilizer　level.　Considered　heavily　synthetically　from　the　branch　structure　,　total　biomass,　the　branch　heavy　and　leaves,　the　vertical　production　structure　on　the　ground　of　F17　,　F9　,　F3　,　F2　,　F1　,　F10　,　F23　is　helpful　to　rational　utilization　resources,　has　high　yield　and　high　quality　potentiality.　By　the　look　of　total　biomass　of　the　different　levels,　C　layer　of　biomass　is　the　biggest,　it　accounts　for　41.85%　of　total　biomass,　A　layer　only　accounts　for　26.75%,　B　layer　lies　between　C　and　A　layer,　accounts　for　31.　4%.　5.　The　vertical　production　structure　of　the　alfalfa　under　the　ground　exists　obvious　difference　in　different　fertilizer　level.　The　vertical　distribution　in　different　soil　layer　of　root　system　biomass　is　different　in　different　fertilizer　treatment.　The　common　characteristic　of　all　treatment　is　the　composition　of　the　biomass　decreases　progressively　with　the　root　gradually　because　of　extending　.　It　is　obviously　that　the　root　system　biomass　of　F4　,　F12　,　F11　,　F2　is　higher　than　other　competence　all　of　them　weight　are　above　37g.　By　the　look　of　vertical　distribution　of　the　volume　of　the　root　system,　alfalfa　root　system　distribute　area　concentrate　on　0~20cm　mainly.　Looking　from　different　treatment,　F4　,　F13　,　F2　,　F11　root　system　are　large　in　volume　;　F8　,　F10　,　F7　,　F15　the　root　system　is　small.　Looking　different　vertical　distribution　of　soil　layer　from　lateral　root,　alfalfa　lateral　root　distribute　area　concentrate　on　0~20cm　on　mainly.　Looking　from　different　level,　F9　,　F2　,　F11　,　F4　,　F1　,　F13　,　F5　have　many　lateral　root;　F2　,　F15　,　F3　,　F10　,　F8　,　F14　have　few　lateral　root.　6.　The　moisture　utilization　efficiency　of　the　alfalfa　exists　obvious　difference　in　different　fertilizer　level.　The　moisture　utilization　efficiency　of　F15　,　F4　,　F12　,　F2　,　F13　is　obviously　higher　than　other　treatments,　more　than　23.70.　It　results　that　these　treatments　have　better　water-saving　effects　and　have　stronger　ability　of　fighting　a　drought　at　the　same　time　.　7.　Mathematics　model　of　yield　has　been　established.　Through　analysing　the　effect　of　output　of　single　factor　,　N　fertile　impact　on　output　obviously,　the　second　is　K　fertile,　P　fertile　has　a　little　effect　on　output.　Through　analysing　the　reciprocation　among　the　factors　,　we　know　N　,　K　do　the　effect　each　other　remarkably　.　Ask　maximum　and　corresponding　quantity　of　fertilizer　with　DPS　data　processing　software　to　output　regression　mode　in　every　code　value　block　of　factor,　consider　both　the　high　yield　and　high-efficient,　the　highest　output　fertilizer　pattern　is　N:　200　kg/hm2　,　P2O5:　0kg/hm2　,　,K2O:　40.55　kg/hm2,　its　output　is　15771.89　kg/hm2.　Benefit　is　12047.03　yuan　/　hm2.