密度和施肥对旱地马铃薯干物质积累、产量和水肥利用的影响

协同提高产量和资源利用效率,是旱作马铃薯高产高效的基础。本研究以陇薯10号为材料,于2017-2019年进行大田试验,设置当地农民习惯栽培(CK)、高产高效栽培(YE)和超高产栽培(HY)3种栽培模式,测定旱地马铃薯叶面积指数(LAI)、叶片SPAD值、冠层光合能力、干物质积累转运、块茎产量、水肥利用效率等指标。结果表明,与CK相比,YE和HY均提高了马铃薯LAI和叶片SPAD值,YE在降雨较少的2017年增幅更明显;二者均减慢了马铃薯块茎膨大后的LAI和叶片SPAD降低幅度,使其冠层光合能力在块茎膨大期和淀粉积累期2年平均提高29.9%、34.7%和40.2%、50.5%。基于较高的LAI和冠层光合能力,YE和HY的地上干物质在块茎膨大期较CK 3年平均增加123.05%和118.53%;同时块茎膨大后同化物对块茎的贡献率增加22.56%和19.29%,使马铃薯产量在2017-2019年平均增加47.93%和47.78%,水分利用效率平均增加77.59%和75.85%,均达到显著差异水平。YE和HY使马铃薯商品薯产量显著增加,收益显著提高,在2017-2019年分别较CK新增纯收益7330.3元hm^-2和6024.6元hm^-2。较大的群体冠层和较高的物质生产促进了植株对N、P、K的积累,YE的N、P利用效率较CK分别提高15.21%和17.20%,N、K收获指数分别提高3.85%和7.79%;HY的N利用效率提高12.37%。YE的WUE、N和P利用效率较HY提高2.05%、2.53%和23.41%,新增纯收益1305.7元hm-2。因此,YE减施缓释尿素40%并有机替代、密度60,000株hm^-2,能够提高水分和养分利用效率,维持马铃薯花后较高的冠层光合能力,促进茎叶干物质向块茎转运,实现作物增产和资源高效利用协同发展,是半干旱区黑膜覆盖马铃薯种植推荐的高产高效模式。

Effects of planting density and fertilization on dry matter accumulation,yield and water-fertilizer utilization of dryland potato

It is important to increase potato production and the natural resource utilization efficiency in dryland farming system.A field experiment was conducted using Longshu 10 with three planting modes from 2017 to 2019,including farmer mode(CK),the mode with high yield and efficiency(YE),and higher yield mode(HY).The leaf area index(LAI),SPAD,photosynthetic rate,accumulation and remobilization of dry matter,water use efficiency(WUE)and fertilizer use efficiency(FUE)was investigated.The results showed that LAI and SPAD were increased in YE and HY compared to CK,and it was more significant in 2017 when there was less rainfall.Meanwhile,less reduction in LAI and SPAD after tubers enlargement resulted in an increase of canopy photosynthetic rate by 29.9%,34.7%(in 2018 and 2019),and 40.2%,50.5%(in 2018 and 2019)during the expanding stage and starch accumulation stage,respectively.Average aboveground dry matter in YE and HY was higher than CK by 123.1%and 118.5%in the enlargement stage due to higher LAI and photosynthetic rate.The contribution rate of assimilation after potato tuber enlargement in YE and HE was higher than CK by 22.56%and 19.29%,resulting in an average potato production increase of 47.93%and 47.78%,and average water use efficiency increased by 77.59%and 75.85%,respectively.YE and HY advantaged in tuber production and income improvement.Compared with CK,the net income increased by 7330.3 Yuan hm^-2 and 6024.6 Yuan hm^-2 in 2017 to 2019,respectively.The accumulation of N,P,and K was significantly enhanced due to large population canopy and high plant biomass accumulation.Compared to CK,N and P use efficiency,and the harvest index of N and P was increased under YE mode by 15.21%,17.20%and 3.85%,7.79%,respectively,and the N use efficiency was increased by 12.37%under HY mode.WUE,N,and P use efficiency of YE mode was higher than HY by 2.05%,2.53%,and 23.41%,respectively,and the net income increased by 1305.7 Yuan hm-2.Therefore,replacement of slow-release urea with organic manure by 40%and improvement of planting density with 60,000 plants hm-2 in YE mode potentially increased in water use efficiency,nutrient use efficiency,high canopy photosynthetic rate maintenances,and remobilization of dry matter from stem and leaf to tubers.In conclusion,YE as a high tuber production and resource use efficiency planting mode,is recommended in semi-arid areas with black-film mulched potato cultivation regime.