荒漠绿洲农田土壤水热动态及硝态氮淋溶特征

doi:10.7522/j.issn.1000-694X.2022.00080

摘要/Abstract

摘要：

灌溉和氮肥的施用是保障干旱荒漠区农田生产的关键措施，但过量的氮肥会随水分淋溶至深层土壤或地下水中，从而导致氮素的损耗和地下水的污染。本研究以黑河中游荒漠绿洲过渡带两种开垦年限的农田土壤（风沙土和灰棕漠土）为研究对象，通过土柱模拟试验监测分析了玉米生育期和休闲期内土壤水分和温度的动态变化及硝态氮（NO $3 -$ -N）的淋溶规律，揭示了不同耕作年限农田土壤中硝态氮损耗的差异。结果表明：新绿洲农田深层渗漏及NO $3 -$ -N的淋失主要发生在苗期—拔节期以及休耕期，深层渗漏年损失量97.65—105.1 mm，占年灌溉水总量（810 mm）的12%—13%，NO $3 -$ -N淋溶年损失量68.1—123.8 kg·hm^-2，占年施氮总量的18.7%—34.2%，休耕期灌水致使生育期内土壤中大量积累的氮素淋溶至深层，NO $3 -$ -N淋失量是当年生育期内NO $3 -$ -N淋失量的2.2倍；开垦年限较长的老绿洲农田在相同灌溉施肥条件下无深层渗漏和NO $3 -$ -N的淋失现象发生，其“蓄水保墒”及抑制水分和NO $3 -$ -N渗漏淋失的生态效应优于开垦年限较短的新垦绿洲农田。因此，为降低土壤水分损失和NO $3 -$ -N淋失风险，建议新绿洲农田生育期内减少春季灌溉次数或降低灌水定额，冬季休耕期降低灌水定额或采取免冬灌措施，以此保证灌溉水资源的优化利用并减少农田氮素的淋失。

关键词: 绿洲农田, 含水率, 温度, 硝态氮, 渗漏, 淋溶

Abstract:

Irrigation and nitrogen fertilizer application are the key measures to ensure farmland production in arid desert areas， but excessive nitrogen fertilizer will leach into deep soil or groundwater， resulting in nitrogen loss and groundwater pollution. In this study， two kinds of farmland soils with different reclamation years in the desert oasis transition zone in the middle reaches of Heihe River were taken as the research objects. Through soil column simulation experiment， the dynamic changes of soil moisture and temperature and the leaching law of nitrate nitrogen in maize growth period and leisure period were monitored and analyzed， and the differences of nitrate nitrogen loss in farmland soils with different cultivation years were revealed. The results showed that the soil water leakage and nitrate leaching of Newly cultivated sandy cropland mainly occurred in the seedling stage to elongation stage and the fallow stage. The annual loss of deep leakage ranged from 97.65 mm to 105.1 mm， accounting for 12%-13% of the total annual irrigation water （810 mm）. The annual loss of NO $3 -$ -N leaching ranged from 68.1 kg·hm^-2 to 123.8 kg·hm^-2， accounting for 18.7%-34.2% of the total annual nitrogen application. Irrigation in fallow period led to the accumulation of a large amount of nitrogen leaching in the soil during the growth period， and the NO $3 -$ -N leaching loss was 2.2 times of that in the current growth period. Under the same irrigation and fertilization conditions， there were no deep seepage and NO $3 -$ -N leaching occurred in the old oasis farmland. Moreover， the “water preservation” effect of old oasis farmland was better than newly cultivated sandy cropland. Therefore， we suggested that reduce the irrigation frequency or irrigation quota in spring during the growing period of newly cultivated sandy farmland， and reduce irrigation quota or no winter irrigation in winter fallow period， so as to ensure the optimal utilization of irrigation water resources and reduce nitrogen leaching loss in farmland.

Key words: oasis farmland, moisture content, temperature, nitrate nitrogen, leakage, leaching

中图分类号:

S274.3

李晶, 何志斌, 王建兵, 马登科, 王丽莎. 荒漠绿洲农田土壤水热动态及硝态氮淋溶特征[J]. 中国沙漠, 2022, 42(5): 245-257.

Jing Li, Zhibin He, Jianbing Wang, Dengke Ma, Lisha Wang. Soil hydrothermal dynamics and nitrate leaching characteristics in farmland in desert oasis[J]. Journal of Desert Research, 2022, 42(5): 245-257.

图/表 13

参考文献 24

1	Beaudoin N， Saad J K， Van Laethem C，et al.Nitrate leaching in intensive agriculture in Northern France： effect of farming practices，soils and crop rotations［J］.Agriculture，Ecosystems & Environment，2005，111（1）：292-310.
2	Thompson R B， Martínez-Gaitan C， Gallardo M，et al.Identification of irrigation and N management practices that contribute to nitrate leaching loss from an intensive vegetable production system by use of a comprehensive survey［J］.Agricultural Water Management，2007，89（3）：261-274.
3	Velthof G L， Lesschen J P， Webb J，et al.The impact of the Nitrates Directive on nitrogen emissions from agriculture in the EU-27 during 2000-2008［J］.Science of the Total Environment，2014（15）：1225-1233.
4	Galloway J N， Townsend A R， Erisman J W，et al.Transformation of the nitrogen cycle： recent trends，questions，and potential solutions［J］.Science，2008，320：889-892.
5	Azusa O， Arunima M， Keiichiro K，et al.Substantial nitrogen pollution embedded in international trade［J］.Nature Geoscience，2016，9（3）：1-5.
6	Fan J， Hao M， Malhi S S.Accumulation of nitrate N in the soil profile and its implications for the environment under dryland agriculture in northern China： a review［J］.Canadian Journal of Soil Science，2010，90（3）：429-440.
7	Young M H， Wierenga P J， Mancino C F.Large weighing lysimeters for water use and deep percolation studies［J］.Soil Science，1996，161（8）：491-501.
8	Li X X， Hu C H， Delgado Jorge A，et al.Increased nitrogen use efficiencies as a key mitigation alternative to reduce nitrate leaching in north china plain［J］.Agricultural Water Management，2007，89（1）：137-147.
9	Yang X L， Lu Y L， Tong Y A，et al.A 5-year lysimeter monitoring of nitrate leaching from wheat-maize rotation system： comparison between optimum N fertilization and conventional farmer N fertilization［J］.Agriculture，Ecosystems & Environment，2015，199（1）：34-42.
10	任理，袁福生，张福锁.冬小麦生长条件下土壤硝态氮淋洗的传递函数模拟和预报［J］.生态学报，2004，24（10）：2281-2288.
11	Su Y Z， Yang R， Liu W J，et al.Evolution of soil structure and fertility after conversion of native sandy desert soil to irrigated cropland in arid region，China［J］.Soil Science，2010，175（5）：246-254.
12	苏永中，张珂，刘婷娜，等.河西边缘绿洲荒漠沙地开垦后土壤性状演变及土壤碳积累研究［J］.中国农业科学，2017，50（9）：1646-1654.
13	王雪峰，苏永中，杨荣.黑河中游绿洲不同开垦年限农田土壤线虫群落特征［J］.应用生态学报，2010，21（8）：2125-2131.
14	苏永中，杨荣，刘文杰，等.基于土壤条件的边缘绿洲典型灌区灌溉需水研究［J］.中国农业科学，2014，47（6）：1128-1139.
15	苏永中，王芳，张智慧，等.河西走廊中段边缘绿洲农田土壤性状与团聚体特征［J］.中国农业科学，2007，40（4）：741-748.
16	刘淑珍，高伟达，任图生.利用最小水分限制范围评价东北黑土区免耕和垄作的土壤水分稳定性［J］.农业工程学报，2020，36（10）：107-115.
17	赵丽雯.河西荒漠绿洲农田玉米蒸腾过程多尺度观测研究［D］.北京：中国科学院大学，2014.
18	聂文果，张盹明，徐先英，等.玉米茎流速率及耗水量研究［J］.中国农学通报，2009，25（7）：230-234.
19	杨荣.荒漠绿洲沙质土壤硝态氮淋溶及其调控研究［D］.北京：中国科学院大学，2009.
20	Nguyen Phuong M， Pue J D， Khoa L V，et al.Impact of regression methods on improved effects of soil structure on soil water retention estimates［J］.Journal of Hydrology，2015，525（4）：598-606.
21	李王成，冯绍元，康绍忠，等.石羊河中游荒漠绿洲区土壤水分的分布特征［J］.水土保持学报，2007，21（3）：138-143.
22	Holland J E， Biswas A.Predicting the mobile water content of vineyard soils in New South Wales，Australia［J］.Agricultural Water Management，2015，148（148）：34-42.
23	刘秀位，苗文芳，王艳哲，等.冬前不同管理措施对土壤温度和冬小麦早期生长的影响［J］.中国生态农业学报，2012，20（9）：1135-1141.
24	苏永中，杨晓，杨荣.黑河中游边缘荒漠-绿洲非饱和带土壤质地对土壤氮积累与地下水氮污染的影响［J］.环境科学，2014，（10）：3683-3691.

农田类型	土质	土层深度/cm	砂粒/%	粉粒/%	黏粒/%	容重/(g·cm^-3)
新绿洲农田	灌耕风沙土	0—20	88.3	9.7	2.0	1.4
		20—40	92.4	6.4	1.2	1.5
		40—60	93.6	5.6	0.8	1.5
		60—80	92.0	6.9	1.1	1.4
		80—100	91.6	7.3	1.1	1.4
老绿洲农田	灌耕灰棕漠土	0—20	65.5	18.2	16.3	1.5
		20—40	76.7	11.5	11.8	1.6
		40—60	87.6	4.9	7.5	1.6
		60—80	91.8	2.3	5.8	1.6
		80—100	92.3	2.1	5.6	1.6

农田类型	土质	土层深度/cm	砂粒/%	粉粒/%	黏粒/%	容重/(g·cm^-3)
新绿洲农田	灌耕风沙土	0—20	88.3	9.7	2.0	1.4
		20—40	92.4	6.4	1.2	1.5
		40—60	93.6	5.6	0.8	1.5
		60—80	92.0	6.9	1.1	1.4
		80—100	91.6	7.3	1.1	1.4
老绿洲农田	灌耕灰棕漠土	0—20	65.5	18.2	16.3	1.5
		20—40	76.7	11.5	11.8	1.6
		40—60	87.6	4.9	7.5	1.6
		60—80	91.8	2.3	5.8	1.6
		80—100	92.3	2.1	5.6	1.6

农田类型	土质	土层深度 /cm	pH	电导率EC /(mS·cm^-1)	有机碳SOC /(g·kg^-1)	全氮TN /(g·kg^-1)	全磷TP /(g·kg^-1)	全钾TK /(g·kg^-1)
新绿洲农田	灌耕风沙土	0—20	8.04	0.11	4.88	0.62	0.49	17.79
		20—40	8.09	0.12	4.43	0.58	0.38	17.65
		40—60	8.76	0.23	3.70	0.51	0.44	17.46
		60—100	8.79	0.20	1.26	0.22	0.27	17.15
		100—140	8.87	0.19	0.67	0.17	0.26	17.12
		140—180	8.93	0.20	0.59	0.12	0.20	16.89
老绿洲农田	灌耕灰棕漠土	0—20	8.15	0.12	6.54	0.82	0.95	34.56
		20—40	8.21	0.13	5.42	0.81	0.87	35.14
		40—60	9.05	0.13	4.97	0.73	0.89	29.68
		60—100	9.13	0.13	3.34	0.45	0.74	28.59
		100—140	9.10	0.14	2.94	0.28	0.69	22.58
		140—180	8.99	0.17	2.77	0.20	0.57	19.58

农田类型	土质	土层深度 /cm	pH	电导率EC /(mS·cm^-1)	有机碳SOC /(g·kg^-1)	全氮TN /(g·kg^-1)	全磷TP /(g·kg^-1)	全钾TK /(g·kg^-1)
新绿洲农田	灌耕风沙土	0—20	8.04	0.11	4.88	0.62	0.49	17.79
		20—40	8.09	0.12	4.43	0.58	0.38	17.65
		40—60	8.76	0.23	3.70	0.51	0.44	17.46
		60—100	8.79	0.20	1.26	0.22	0.27	17.15
		100—140	8.87	0.19	0.67	0.17	0.26	17.12
		140—180	8.93	0.20	0.59	0.12	0.20	16.89
老绿洲农田	灌耕灰棕漠土	0—20	8.15	0.12	6.54	0.82	0.95	34.56
		20—40	8.21	0.13	5.42	0.81	0.87	35.14
		40—60	9.05	0.13	4.97	0.73	0.89	29.68
		60—100	9.13	0.13	3.34	0.45	0.74	28.59
		100—140	9.10	0.14	2.94	0.28	0.69	22.58
		140—180	8.99	0.17	2.77	0.20	0.57	19.58

农田	土层/cm	4月
新绿洲农田	0—20	39.50±0.91^c	35.39±1.35^cd	29.33±0.67^cd	24.02±1.20^cd	31.43±1.76^bc	30.47±2.12^cd
	20—40	30.51±8.31^de	28.82±5.62^e	19.64±1.66^e	9.80±8.89^d	17.61±15.91^d	19.12±17.39^d
	40—60	24.59±2.22^e	27.82±1.62^e	20.84±1.28^e	13.08±0.89^d	15.01±13.02^d	24.08±1.72^cd
	60—80	27.97±0.73^de	33.51±2.71^de	24.98±6.31^de	29.26±9.79^bc	26.96±1.48^cd	32.84±5.71^c
	80—100	26.83±1.90^e	31.07±0.85^de	26.48±0.95^de	18.92±6.24^cd	21.49±4.30^cd	25.87±0.27^cd
	100—120	33.56±1.90^cd	35.14±1.61^cd	31.55±2.55^cd	19.90±2.20^cd	24.56±2.24^cd	30.32±1.56^cd
	120—140	38.18±1.81^cd	38.21±1.61^c	36.93±2.70^c	24.80±3.08^cd	26.16±2.95^cd	33.97±1.65^bc
	140—160	49.25±4.14^b	49.24±4.11^b	48.68±4.97^b	34.44±1.71^ab	33.30±2.67^ab	44.92±2.56^b
	160—180	65.41±3.53^a	66.73±4.43^a	67.09±4.48^a	44.46±6.42^a	41.49±6.42^a	62.02±4.23^a
老绿洲农田	0—20	41.04±5.56^b	44.43±7.33^b	43.69±7.6^ab	33.44±6.79^b	37.16±3.96^a	35.71±5.15^b
	20—40	45.07±6.08^b	46.84±7.80^b	44.59±6.27^ab	32.85±3.13^b	37.82±4.29^a	39.07±7.89^ab
	40—60	50.12±5.87^a	55.27±7.50^ab	52.15±7.23^ab	37.39±5.49^b	42.23±4.30^a	47.56±9.18^ab
	60—80	49.78±1.10^ab	55.10±1.88^ab	52.08±1.48^ab	38.86±2.10^b	41.39±1.28^a	48.74±1.83^ab
	80—100	48.51±3.66^ab	52.89±2.90^ab	52.24±4.55^ab	38.90±3.64^b	39.31±2.31^a	46.69±1.07^ab
	100—120	49.87±7.37^ab	52.97±7.01^ab	52.33±6.67^ab	43.61±9.05^ab	42.33±8.65^a	45.94±6.77^ab
	120—140	46.99±7.20^ab	47.96±7.71^b	48.39±8.54^ab	39.20±12.48^b	36.81±9.34^a	39.93±6.25^ab
	140—160	48.43±4.08^ab	52.96±4.29^ab	55.06±3.77^a	49.95±14.70^ab	37.72±7.42^a	41.81±6.32^ab
	160 —180	35.36±11.12^b	37.03±12.95^b	38.38±14.08^b	30.90±16.94^b	23.02±12.56^a	50.42±11.77^a